'Return the rest of the word, e.g. completing ``isinstance``::
isinstan# <-- Cursor is here
would return the string \'ce\'. It also adds additional stuff, depending
on your `settings.py`.
Assuming the following function definition::
def foo(param=0):
pass
completing ``foo(par`` would give a ``Completion`` which `complete`
would be `am=`'

@property
def complete(self):

    return self._complete(True)
