---------- g1 ----------
  8           0 LOAD_CONST               0 (None) 
              3 YIELD_VALUE          
              4 POP_TOP              

  9           5 LOAD_CONST               1 (42) 
              8 YIELD_VALUE          
              9 POP_TOP              
             10 LOAD_CONST               0 (None) 
             13 RETURN_VALUE         
---------- g2 ----------
 12           0 LOAD_GLOBAL              0 (x) 
              3 YIELD_FROM           
              4 POP_TOP              
              5 LOAD_CONST               0 (None) 
              8 RETURN_VALUE         
---------- g3 ----------
 15           0 LOAD_FAST                0 (x) 
              3 YIELD_FROM           
              4 STORE_FAST               0 (x) 
              7 LOAD_CONST               0 (None) 
             10 RETURN_VALUE