def __iadd__(self, other):
if isinstance(other, TokenWithPosition):<EOL><INDENT>new = TokenWithPosition(self.text + other.text, self.position)<EOL><DEDENT>else:<EOL><INDENT>new = TokenWithPosition(self.text + other, self.position)<EOL><DEDENT>return new<EOL>
Implements addition in the form of TextWithPosition(...) += ...

        >>> t1 = TokenWithPosition('as', 0)
        >>> t1 += 'df'
        >>> str(t1)
        'asdf'
        >>> t1.position
        0