{
  "javascript": {
    "builtins": {
      "WeakMap": {
        "__compat": {
          "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/WeakMap",
          "support": {
            "webview_android": {
              "version_added": "36"
            },
            "chrome": {
              "version_added": "36"
            },
            "chrome_android": {
              "version_added": "36"
            },
            "edge": {
              "version_added": "12"
            },
            "edge_mobile": {
              "version_added": "12"
            },
            "firefox": {
              "version_added": "6"
            },
            "firefox_android": {
              "version_added": "6"
            },
            "ie": {
              "version_added": "11"
            },
            "nodejs": {
              "version_added": true
            },
            "opera": {
              "version_added": "23"
            },
            "opera_android": {
              "version_added": "23"
            },
            "safari": {
              "version_added": "8"
            },
            "safari_ios": {
              "version_added": "8"
            },
            "samsunginternet_android": {
              "version_added": true
            }
          },
          "status": {
            "experimental": false,
            "standard_track": true,
            "deprecated": false
          }
        },
        "weakmap_iterable": {
          "__compat": {
            "description": "<code>new WeakMap(iterable)</code>",
            "support": {
              "webview_android": {
                "version_added": "38"
              },
              "chrome": {
                "version_added": "38"
              },
              "chrome_android": {
                "version_added": "38"
              },
              "edge": {
                "version_added": "12"
              },
              "edge_mobile": {
                "version_added": "12"
              },
              "firefox": {
                "version_added": "36"
              },
              "firefox_android": {
                "version_added": "36"
              },
              "ie": {
                "version_added": false
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": "25"
              },
              "opera_android": {
                "version_added": "25"
              },
              "safari": {
                "version_added": "9"
              },
              "safari_ios": {
                "version_added": "9"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": true,
              "deprecated": false
            }
          }
        },
        "weakmap_null": {
          "__compat": {
            "description": "<code>new WeakMap(null)</code>",
            "support": {
              "webview_android": {
                "version_added": true
              },
              "chrome": {
                "version_added": true
              },
              "chrome_android": {
                "version_added": true
              },
              "edge": {
                "version_added": "12"
              },
              "edge_mobile": {
                "version_added": "12"
              },
              "firefox": {
                "version_added": "37"
              },
              "firefox_android": {
                "version_added": "37"
              },
              "ie": {
                "version_added": "11"
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": null
              },
              "opera_android": {
                "version_added": null
              },
              "safari": {
                "version_added": "8"
              },
              "safari_ios": {
                "version_added": "8"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": true,
              "deprecated": false
            }
          }
        },
        "weakmap_without_new_throws": {
          "__compat": {
            "description": "<code>WeakMap()</code> without <code>new</code> throws",
            "support": {
              "webview_android": {
                "version_added": true
              },
              "chrome": {
                "version_added": true
              },
              "chrome_android": {
                "version_added": true
              },
              "edge": {
                "version_added": "12"
              },
              "edge_mobile": {
                "version_added": "12"
              },
              "firefox": {
                "version_added": "42"
              },
              "firefox_android": {
                "version_added": "42"
              },
              "ie": {
                "version_added": "11"
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": true
              },
              "opera_android": {
                "version_added": true
              },
              "safari": {
                "version_added": "9"
              },
              "safari_ios": {
                "version_added": "9"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": true,
              "deprecated": false
            }
          }
        },
        "clear": {
          "__compat": {
            "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/WeakMap/clear",
            "support": {
              "webview_android": {
                "version_added": "36",
                "version_removed": "43"
              },
              "chrome": {
                "version_added": "36",
                "version_removed": "43"
              },
              "chrome_android": {
                "version_added": "36",
                "version_removed": "43"
              },
              "edge": {
                "version_added": false
              },
              "edge_mobile": {
                "version_added": false
              },
              "firefox": {
                "version_added": "20",
                "version_removed": "46"
              },
              "firefox_android": {
                "version_added": "20",
                "version_removed": "46"
              },
              "ie": {
                "version_added": "11"
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": "25",
                "version_removed": "30"
              },
              "opera_android": {
                "version_added": "25",
                "version_removed": "30"
              },
              "safari": {
                "version_added": "8",
                "version_removed": "9"
              },
              "safari_ios": {
                "version_added": "8",
                "version_removed": "9"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": false,
              "deprecated": true
            }
          }
        },
        "delete": {
          "__compat": {
            "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/WeakMap/delete",
            "support": {
              "webview_android": {
                "version_added": "36"
              },
              "chrome": {
                "version_added": "36"
              },
              "chrome_android": {
                "version_added": "36"
              },
              "edge": {
                "version_added": true
              },
              "edge_mobile": {
                "version_added": true
              },
              "firefox": {
                "version_added": "6",
                "notes": "Prior to Firefox 38, this method threw a <code>TypeError</code> when the key parameter was not an object. This has been fixed in version 38 and later to return <code>false</code> as per the ES2015 standard."
              },
              "firefox_android": {
                "version_added": "6",
                "notes": "Prior to Firefox 38, this method threw a <code>TypeError</code> when the key parameter was not an object. This has been fixed in version 38 and later to return <code>false</code> as per the ES2015 standard."
              },
              "ie": {
                "version_added": "11"
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": "23"
              },
              "opera_android": {
                "version_added": "23"
              },
              "safari": {
                "version_added": "8"
              },
              "safari_ios": {
                "version_added": "8"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": true,
              "deprecated": false
            }
          }
        },
        "get": {
          "__compat": {
            "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/WeakMap/get",
            "support": {
              "webview_android": {
                "version_added": "36"
              },
              "chrome": {
                "version_added": "36"
              },
              "chrome_android": {
                "version_added": "36"
              },
              "edge": {
                "version_added": true
              },
              "edge_mobile": {
                "version_added": true
              },
              "firefox": {
                "version_added": "6",
                "notes": "Prior to Firefox 38, this method threw a <code>TypeError</code> when the key parameter was not an object. However, the ES2015 specification specifies to return <code>undefined</code> instead. Furthermore, <code>WeakMap.prototype.get</code> accepted an optional second argument as a fallback value, which is not part of the standard. Both non-standard behaviors are removed in version 38 and higher."
              },
              "firefox_android": {
                "version_added": "6",
                "notes": "Prior to Firefox 38, this method threw a <code>TypeError</code> when the key parameter was not an object. However, the ES2015 specification specifies to return <code>undefined</code> instead. Furthermore, <code>WeakMap.prototype.get</code> accepted an optional second argument as a fallback value, which is not part of the standard. Both non-standard behaviors are removed in version 38 and higher."
              },
              "ie": {
                "version_added": "11"
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": "23"
              },
              "opera_android": {
                "version_added": "23"
              },
              "safari": {
                "version_added": "8"
              },
              "safari_ios": {
                "version_added": "8"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": true,
              "deprecated": false
            }
          }
        },
        "has": {
          "__compat": {
            "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/WeakMap/has",
            "support": {
              "webview_android": {
                "version_added": "36"
              },
              "chrome": {
                "version_added": "36"
              },
              "chrome_android": {
                "version_added": "36"
              },
              "edge": {
                "version_added": true
              },
              "edge_mobile": {
                "version_added": true
              },
              "firefox": {
                "version_added": "6",
                "notes": "Prior to Firefox 38, this method threw a <code>TypeError</code> when the key parameter was not an object. This has been fixed in version 38 and later to return <code>false</code> as per the ES2015 standard."
              },
              "firefox_android": {
                "version_added": "6",
                "notes": "Prior to Firefox 38, this method threw a <code>TypeError</code> when the key parameter was not an object. This has been fixed in version 38 and later to return <code>false</code> as per the ES2015 standard."
              },
              "ie": {
                "version_added": "11"
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": "23"
              },
              "opera_android": {
                "version_added": "23"
              },
              "safari": {
                "version_added": "8"
              },
              "safari_ios": {
                "version_added": "8"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": true,
              "deprecated": false
            }
          }
        },
        "prototype": {
          "__compat": {
            "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/WeakMap/prototype",
            "support": {
              "webview_android": {
                "version_added": "36"
              },
              "chrome": {
                "version_added": "36"
              },
              "chrome_android": {
                "version_added": "36"
              },
              "edge": {
                "version_added": true
              },
              "edge_mobile": {
                "version_added": true
              },
              "firefox": {
                "version_added": "6"
              },
              "firefox_android": {
                "version_added": "6"
              },
              "ie": {
                "version_added": "11"
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": "23"
              },
              "opera_android": {
                "version_added": "23"
              },
              "safari": {
                "version_added": "8"
              },
              "safari_ios": {
                "version_added": "8"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": true,
              "deprecated": false
            }
          }
        },
        "set": {
          "__compat": {
            "mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/WeakMap/set",
            "support": {
              "webview_android": {
                "version_added": "36"
              },
              "chrome": {
                "version_added": "36"
              },
              "chrome_android": {
                "version_added": "36"
              },
              "edge": {
                "version_added": true
              },
              "edge_mobile": {
                "version_added": true
              },
              "firefox": {
                "version_added": "6",
                "notes": "Prior to Firefox 38, this method threw a <code>TypeError</code> when the key parameter was not an object. This has been fixed in version 38 and later to return <code>false</code> as per the ES2015 standard."
              },
              "firefox_android": {
                "version_added": "6",
                "notes": "Prior to Firefox 38, this method threw a <code>TypeError</code> when the key parameter was not an object. This has been fixed in version 38 and later to return <code>false</code> as per the ES2015 standard."
              },
              "ie": {
                "version_added": "11",
                "partial_implementation": true,
                "notes": "Returns 'undefined' instead of the 'Map' object."
              },
              "nodejs": {
                "version_added": true
              },
              "opera": {
                "version_added": "23"
              },
              "opera_android": {
                "version_added": "23"
              },
              "safari": {
                "version_added": "8"
              },
              "safari_ios": {
                "version_added": "8"
              },
              "samsunginternet_android": {
                "version_added": true
              }
            },
            "status": {
              "experimental": false,
              "standard_track": true,
              "deprecated": false
            }
          }
        }
      }
    }
  }
}