Train short term memory with given spirograph.

        :param spiro:
            :py:class:`SpiroArtifact` object

def learn(self, spiro, iterations=1):
        '''Train short term memory with given spirograph.

        :param spiro:
            :py:class:`SpiroArtifact` object
        '''
        for i in range(iterations):
            self.stmem.train_cycle(spiro.obj.flatten())