test some adjacent toffoli gates

lib.py

@@ -650,6 +650,7 @@ class UnitaryOperator(LinearTransformation, UnitaryMatrix):
                     extended_m[1].append(I)
                 else:
                     this_partial = self.partials[next_partial]
+                    # TODO: This works only with C_partial :(((
                     if this_partial == C_partial:
                         extended_m[0].append(s("|0><0|"))
                         extended_m[1].append(s("|1><1|"))
@@ -1002,9 +1003,12 @@ def test_partials():
     assert CNOT.on(s("|1000>"), which_qbit=[0, 3]) == s("|1001>")
 
     # test Toffoli gate
-    # assert TOFF.on(s("|000>")) == s("|000>")
-    # assert TOFF.on(s("|100>")) == s("|100>")
-    # assert TOFF.on(s("|110>")) == s("|111>")
+    assert TOFF.on(s("|000>")) == s("|000>")
+    assert TOFF.on(s("|100>")) == s("|100>")
+    assert TOFF.on(s("|110>")) == s("|111>")
+    assert TOFF.on(s("|111>")) == s("|110>")
+
+    # TODO: This doesn't work :(((
     # assert TOFF.on(s("|1100>"), which_qbit=[0, 1, 3]) == s("|1101>")
 
 
@@ -1275,13 +1279,6 @@ class QuantumCircuit(object):
             self.add_row(row_data)
 
     def compose_quantum_state(self, step):
-        partials = [op for op in step if isinstance(op, PartialQubit)]
-        # TODO: No more than 1 TwoQubitGate **OR** UnitaryOperator can be
-        #  used in a step
-        for partial in partials:
-            two_qubit_op = partial.operator
-            two_qubit_op.verify_step()
-            return two_qubit_op.compose(step)
         return reduce((lambda x, y: x * y), step)
 
     def step(self):