function isRegExp(value) {
      return value ? (typeof value == 'object' && toString.call(value) == regexpClass) : false;
    }
Checks if `value` is a regular expression.

@static
@memberOf _
@category Objects
@param {*} value The value to check.
@returns {boolean} Returns `true` if the `value` is a regular expression, else `false`.
@example

_.isRegExp(/moe/);
// => true