code: def build_rotation(vec3):
          
          if not isinstance(vec3, Vector3):
              raise ValueError("rotAmt must be a Vector3")
          return Matrix4.x_rotate(vec3.x) * Matrix4.y_rotate(vec3.y) * Matrix4.z_rotate(vec3.z)
docs: Build a rotation matrix.
          vec3 is a Vector3 defining the axis about which to rotate the object.