{{alias}}( str[, n][, options] )
    Returns the first character(s) of a string.

    Parameters
    ----------
    str: string
        Input string.

    n: integer (optional)
        Number of characters to return. Default: 1.

    options: Object (optional)
        Options.

    options.mode: string (optional)
        Type of characters to return. The following modes are supported:

        - grapheme: grapheme clusters. Appropriate for strings containing visual
          characters which can span multiple Unicode code points (e.g., emoji).
        - code_point: Unicode code points. Appropriate for strings containing
          visual characters which are comprised of more than one Unicode code
          unit (e.g., ideographic symbols and punctuation and mathematical
          alphanumerics).
        - code_unit': UTF-16 code units. Appropriate for strings containing
          visual characters drawn from the basic multilingual plane (BMP) (e.g.,
          common characters, such as those from the Latin, Greek, and Cyrillic
          alphabets).

        Default: 'grapheme'.

    Returns
    -------
    out: string
        Output string.

    Examples
    --------
    > var out = {{alias}}( 'beep' )
    'b'
    > out = {{alias}}( 'Boop', 1 )
    'B'
    > out = {{alias}}( 'foo bar', 5 )
    'foo b'

    See Also
    --------