def pop_bytes(self, nbytes, force=False):
data = self.read_bytes(self.STACK, nbytes, force=force)<EOL>self.STACK += nbytes<EOL>return data<EOL>
Read `nbytes` from the stack, increment the stack pointer, and return
data.

:param int nbytes: How many bytes to read
:param force: whether to ignore memory permissions
:return: Data read from the stack