code: function baseIteratee(func) {
      if (typeof func == 'function') {
        return func;
      }
      if (func == null) {
        return identity;
      }
      return (typeof func == 'object' ? baseMatches : baseProperty)(func);
    }
docs: The base implementation of `_.iteratee`.
  
  @private
  @param {*} [value=_.identity] The value to convert to an iteratee.
  @returns {Function} Returns the iteratee.