code: def as_dict(self):
          
          pwinput_dict = {'structure': self.structure.as_dict(),
                          'pseudo': self.pseudo,
                          'sections': self.sections,
                          'kpoints_mode': self.kpoints_mode,
                          'kpoints_grid': self.kpoints_grid,
                          'kpoints_shift': self.kpoints_shift}
          return pwinput_dict
docs: Create a dictionary representation of a PWInput object
          
          Returns:
              dict