/**
 * Unescapes HTML entities in a string
 * @param string_ - The string to unescape
 * @returns The unescaped string with HTML entities converted back to their original characters
 * @example
 * ```typescript
 * unescapeHtml("<script>alert("Hello");</script>");
 * // Returns: "<script>alert(\"Hello\");</script>"
 *
 * unescapeHtml("Tom &amp; Jerry");
 * // Returns: "Tom & Jerry"
 *
 * unescapeHtml("5 &lt; 10 &amp;&amp; 10 &gt; 5");
 * // Returns: "5 < 10 && 10 > 5"
 * ```
 */
export declare const unescapeHtml: (string_: string) => string;