'Gets the current sigmask. If it\'s blank, a new one is created (of sigsetsize).
:param sigsetsize: the size (in *bytes* of the sigmask set)
:return: the sigmask'

def sigmask(self, sigsetsize=None):

    if (self._sigmask is None):
        if (sigsetsize is not None):
            sc = self.state.se.any_int(sigsetsize)
            self.state.add_constraints((sc == sigsetsize))
            self._sigmask = self.state.se.BVS('initial_sigmask', (sc * 8))
        else:
            self._sigmask = self.state.se.BVS('initial_sigmask', self.sigmask_bits)
    return self._sigmask
