def _fitch_state(self, node, pos):
state = self._fitch_intersect([k.state[pos] for k in node.clades])<EOL>if len(state) == <NUM_LIT:0>:<EOL><INDENT>state = np.concatenate([k.state[pos] for k in node.clades])<EOL><DEDENT>return state<EOL>
Determine the Fitch profile for a single character of the node's sequence.
The profile is essentially the intersection between the children's
profiles or, if the former is empty, the union of the profiles.

Parameters
----------

 node : PhyloTree.Clade:
    Internal node which the profiles are to be determined

 pos : int
    Position in the node's sequence which the profiles should
    be determinedf for.

Returns
-------
 state : numpy.array
    Fitch profile for the character at position pos of the given node.