code: def finish(self):
          
          self._vertices = np.array(self._vertices, 'float32')
          if self._faces:
              self._faces = np.array(self._faces, 'uint32')
          else:
              # Use vertices only
              self._vertices = np.array(self._v, 'float32')
              self._faces = None
          if self._normals:
              self._normals = np.array(self._normals, 'float32')
          else:
              self._normals = self._calculate_normals()
          if self._texcords:
              self._texcords = np.array(self._texcords, 'float32')
          else:
              self._texcords = None
  
          return self._vertices, self._faces, self._normals, self._texcords
docs: Converts gathere lists to numpy arrays and creates
          BaseMesh instance.