func_code: def overlap(x1=0, y1=0, r1=1, x2=0, y2=0, r2=1):
      a = (x2 - x1) ** 2
      b = (y2 - y1) ** 2
      c = (a + b) ** 0.5
      total_r = r1 + r2
      if c < total_r:
          return True
      else:
          return False