#**Context:** This chunk provides APIs for user session management and logging in ServiceNow's ATF. It includes operations like impersonating a user, creating a user with specific roles and groups, logging messages for tests, performing record queries, and inserting records into tables. These functionalities are crucial for simulating different user interactions and ensuring databases reflect expected test results.
```typescript
// Impersonates the specified user in the current session for the duration of the test or until another user is impersonated.
atf.server.impersonate({
  $id: Now.ID[''], // string | guid, mandatory
  user: get_sys_id('sys_user', ''), // sys_id | Record<'sys_user'>
}): { 
  user: '' // sys_id of the user
};

// Create a user with specified roles and groups. Optionally impersonate the user in the current session for the duration of the test or until another user is impersonated.
atf.server.createUser({ // all props are mandatory
  $id: Now.ID[''], // string | guid, mandatory
  fieldValues: {}, // a valid JSON object, field must be snake_case and double-quoted and values must be double-quoted with properly escaped JSON values, example: { "user_name": "john.doe", "home_phone": "18581234567" }. Do NOT include first_name or last_name
  groups: [get_sys_id('sys_user_group', '')], // array of sys_id | Record<'sys_user_group'>
  roles: [get_sys_id('sys_user_role', '')], // array of sys_id | Role;
  impersonate: false, // boolean
  firstName: '', // string
  lastName: '', // string
}): { user: string; };

// Logs a message that can contain a variable or other information pertaining to the test. This message will be stored as a step result upon test completion.
atf.server.log({
    $id: Now.ID[''], // string | guid, mandatory
    log: ''; // string
}): void;

// Perform a database query to verify if a record matching the conditions set in this step are met
atf.server.recordQuery({ // all props are mandatory
  $id: Now.ID[''], // string | guid, mandatory
  table: '', // table name
  fieldValues: '', // string, servicenow encoded query
  enforceSecurity: false, // boolean;
  assert: 'records_match_query', // 'records_match_query' | 'no_records_match_query';
}): { table: string; 
    firstRecord: string; // sys_id of the first record
};

// Inserts a record into a table. Specify the field values to set on the new record, outputs the table and the sys_id of the new record.
atf.server.recordInsert({ // all props are mandatory
    $id: Now.ID[''], // string | guid, mandatory
    table: '', // table name
    fieldValues: {}, // a valid JSON object, field must be snake_case and double-quoted and values must be double-quoted with properly escaped JSON values, example: { "field_one": "value1", "field_two": "value2" }
    assert: '', // 'record_successfully_inserted' | 'record_not_inserted';
    enforceSecurity: false, // boolean;
 }): { table: string;
    recordId: string; // sys_id of the new record
};
```