docs: def strained_001(self, target):
          '''
          Returns an instance of ``IIIVZincBlendeStrained001``, which is a
          biaxial-strained III-V zinc blende binary alloy grown on a (001)
          surface.
          
          Parameters
          ----------
          target : Alloy with ``a`` parameter or float
              Growth substrate, assumed to have a (001) surface, or out-of-plane
              strain, which is negative for tensile strain and positive for
              compressive strain. This is the strain measured by X-ray
              diffraction (XRD) symmetric omega-2theta scans.
          '''
          if isinstance(target, Alloy):
              return IIIVZincBlendeStrained001(unstrained=self,
                                               substrate=target)
          else:
              return IIIVZincBlendeStrained001(unstrained=self,
                                               strain_out_of_plane=target)