input: 
  class CreateVector3DClass:
      """
      Create a Python class which represents a 3D Vector with an initializer to set the x, y, z components and a string representation method.
      >>> v = Vector3D(1, 2, 3)
      >>> str(v)
      '(1, 2, 3)'
      """
      class Vector3D:
          def __init__(self, x, y, z):
              self.x = x
              self.y = y
              self.z = z
          
          def __str__(self):
              return "(" + str(self.x) + ", " + str(self.y) + ", " + str(self.z) + ")"
  
output:     
  class CreateVector3DClass:
      """
      Create a Python class which represents a 3D Vector with an initializer to set the x, y, z components and a string representation method.
      >>> v = Vector3D(1, 2, 3)
      >>> str(v)
      '(1, 2, 3)'
      """
      class Vector3D:
          def __init__(self, x, y, z):
              self.x = x
              self.y = y
              self.z = z
          
          def __str__(self):
              return "(" + str(self.x) + ", " + str(self.y) + ", " + str(self.z) + ")"
  