def _check_bits(self, args, amap):
<EOL>for wire in args:<EOL><INDENT>if wire not in amap:<EOL><INDENT>raise DAGCircuitError("<STR_LIT>" %<EOL>(wire[<NUM_LIT:0>].name, wire[<NUM_LIT:1>]))<EOL><DEDENT><DEDENT>
Check the values of a list of (qu)bit arguments.

        For each element of args, check that amap contains it.

        Args:
            args (list): (register,idx) tuples
            amap (dict): a dictionary keyed on (register,idx) tuples

        Raises:
            DAGCircuitError: if a qubit is not contained in amap