def __iadd__(self, other):
if isinstance(other, Tribe):<EOL><INDENT>self.templates += other.templates<EOL><DEDENT>elif isinstance(other, Template):<EOL><INDENT>self.templates.append(other)<EOL><DEDENT>else:<EOL><INDENT>raise TypeError('<STR_LIT>')<EOL><DEDENT>return self<EOL>
Add in place: '+='

.. rubric:: Example

>>> tribe = Tribe(templates=[Template(name='a')])
>>> tribe += Tribe(templates=[Template(name='b')])
>>> print(tribe)
Tribe of 2 templates
>>> tribe += Template(name='c')
>>> print(tribe)
Tribe of 3 templates