Skips all spaces and comments.
        :return: The first character that follows the skipped spaces and comments or
                None if the end of the json string has been reached.

def _skip_spaces_and_peek(self):
        """ Skips all spaces and comments.
        :return: The first character that follows the skipped spaces and comments or
                None if the end of the json string has been reached.
        """
        while 1:
            # skipping spaces
            self.skip_chars(self.end, lambda x: x in self.spaces)
            c = self.peek()
            if not self.params.allow_comments:
                return c
            if c != '/':
                return c
            d = self.peek(1)
            if d == '/':
                self.skip_to(self.pos + 2)
                self._skip_singleline_comment()
            elif d == '*':
                self.skip_to(self.pos + 2)
                self._skip_multiline_comment()
            else:
                return c