code: def from_mapping(cls, x0, x1):
          
          t = cls()
          t.set_mapping(x0, x1)
          return t
docs: Create an STTransform from the given mapping
  
          See `set_mapping` for details.
  
          Parameters
          ----------
          x0 : array-like
              Start.
          x1 : array-like
              End.
  
          Returns
          -------
          t : instance of STTransform
              The transform.