code: def have_graph(name):
      '''return true if we have a graph of the given name'''
      for g in mestate.graphs:
          if g.name == name:
              return True
      return Falsf have_graph(name):
      '''return true if we have a graph of the given name'''
      for g in mestate.graphs:
          if g.name == name:
              return True
      return False
docs: return true if we have a graph of the given name