func_code: def overlap(x1=0, y1=0, r1=1, x2=0, y2=0, r2=1):
      dis = ((x1 - x2) ** 2 + (y1 + y2) ** 2) ** 0.5
      if r1 + r2 >= dis and dis != 0:
          return True
      elif dis == 0 and r1 == r2:
          return True
      else:
          return False