function trimRight(subject, whitespace) {
    var subjectString = coerceToString(subject);

    if (whitespace === '' || subjectString === '') {
      return subjectString;
    }

    var whitespaceString = toString(whitespace);

    if (isNil(whitespaceString)) {
      return subjectString.replace(REGEXP_TRIM_RIGHT, '');
    }

    var matchWhitespace = true;
    return reduceRight.call(
      subjectString,
      function(trimmed, character) {
        if (matchWhitespace && includes(whitespaceString, character)) {
          return trimmed;
        }

        matchWhitespace = false;
        return character + trimmed;
      },
      ''
    );
  }
Removes whitespaces from the right side of the `subject`.

@function trimRight
@static
@since 1.0.0
@memberOf Manipulate
@param {string} [subject=''] The string to trim.
@param {string} [whitespace=whitespace] The whitespace characters to trim. List all characters that you want to be stripped.
@return {string} Returns the trimmed string.
@example
v.trimRight('the fire rises   ');
// => 'the fire rises'

v.trimRight('do you feel in charge?!!!', '!');
// => 'do you feel in charge?'