code: def set_faces(self, faces):
          
          self._faces = faces
          self._edges = None
          self._edges_indexed_by_faces = None
          self._vertex_faces = None
          self._vertices_indexed_by_faces = None
          self.reset_normals()
          self._vertex_colors_indexed_by_faces = None
          self._face_colors_indexed_by_faces = None
docs: Set the faces
  
          Parameters
          ----------
          faces : ndarray
              (Nf, 3) array of faces. Each row in the array contains
              three indices into the vertex array, specifying the three corners
              of a triangular face.