function trimLeft(string, chars, guard) {
	      var value = string;
	      string = baseToString(string);
	      if (!string) {
	        return string;
	      }
	      if (guard ? isIterateeCall(value, chars, guard) : chars == null) {
	        return string.slice(trimmedLeftIndex(string));
	      }
	      return string.slice(charsLeftIndex(string, (chars + '')));
	    }
Removes leading whitespace or specified characters from `string`.

@static
@memberOf _
@category String
@param {string} [string=''] The string to trim.
@param {string} [chars=whitespace] The characters to trim.
@param- {Object} [guard] Enables use as a callback for functions like `_.map`.
@returns {string} Returns the trimmed string.
@example

_.trimLeft('  abc  ');
// => 'abc  '

_.trimLeft('-_-abc-_-', '_-');
// => 'abc-_-'