Sets what extensions are supported by the local party.

def _set_extensions(self, params):
        """
        Sets what extensions are supported by the local party.
        """
        extensions = []
        if self._local_partial_reliability:
            params.append((SCTP_PRSCTP_SUPPORTED, b''))
            extensions.append(ForwardTsnChunk.type)

        extensions.append(ReconfigChunk.type)
        params.append((SCTP_SUPPORTED_CHUNK_EXT, bytes(extensions)))