docs: def copy(self):
          """Make a deep copy of this object.
          
          Example::
  
              >>> c2 = c.copy()
          
          """
          vec1 = np.copy(self.scoef1._vec)
          vec2 = np.copy(self.scoef2._vec)
          return VectorCoefs(vec1, vec2, self.nmax, self.mmax)