code: def test_base_hamilton():
      """Test BaseHamilton. Checks that it doesn't raise errors."""
      from deepchem.utils.dft_utils import BaseHamilton
  
      class MyHamilton(BaseHamilton):
          def __init__(self):
              self._nao = 2
              self._kpts = torch.tensor([[0.0, 0.0, 0.0]])
              self._df = None
  
          @property
          def nao(self):
              return self._nao
  
          @property
          def kpts(self):
              return self._kpts
  
          @property
          def df(self):
              return self._df
  
          def build(self):
              return self
  
          def get_nuclattr(self):
              return torch.ones((1, 1, self.nao, self.nao))
  
      ham = MyHamilton()
      hamilton = ham.build()
      assert torch.allclose(
          hamilton.get_nuclattr(),
          torch.tensor([[[[1.0, 1.0], [1.0, 1.0]]]]),
      )
  
file_path: deepchem/deepchem/utils/test/test_dft_utils.py
imports: import pytest
  import numpy
  from typing import Union
label_desc: Use image node_id 13 for calling a global function with example usage: test_base_hamilton() and returns: self, self, self, self, torch