def split(self, point=None):
if point is None:<EOL><INDENT>point = len(self) / <NUM_LIT:2><EOL><DEDENT>r1 = Sequence(self.name + "<STR_LIT>", self.sequenceData[:point])<EOL>r2 = Sequence(self.name + "<STR_LIT>", self.sequenceData[point:])<EOL>return r1, r2<EOL>
Split this sequence into two halves and return them. The original
sequence remains unmodified.

:param point: defines the split point, if None then the centre is used
:return: two Sequence objects -- one for each side