code: function padLeft(string, length, chars) {
        string = string == null ? '' : String(string);
        return createPad(string, length, chars) + string;
      }
docs: Pads `string` on the left side if it is shorter then the given padding
  length. The `chars` string may be truncated if the number of padding
  characters exceeds the padding length.
  
  @static
  @memberOf _
  @category Strings
  @param {string} [string=''] The string to pad.
  @param {number} [length=0] The padding length.
  @param {string} [chars=' '] The string used as padding.
  @returns {string} Returns the padded string.
  @example
  
  _.padLeft('abc', 6);
  // => '   abc'
  
  _.padLeft('abc', 6, '_-');
  // => '_-_abc'
  
  _.padLeft('abc', 3);
  // => 'abc'