':return: a corpus view that acts as a list of
``PropBankInstance`` objects, one for each noun in the corpus.'

def instances(self, baseform=None):

    kwargs = {}
    if (baseform is not None):
        kwargs[u'instance_filter'] = (lambda inst: (inst.baseform == baseform))
    return StreamBackedCorpusView(self.abspath(self._propfile), (lambda stream: self._read_instance_block(stream, **kwargs)), encoding=self.encoding(self._propfile))
