text: import pytest
  import foyer
  
  
  def test_basic_import():
      assert 'forcefields' in dir(foyer)
  
  
  def test_loading_forcefields():
      #funcs = [func for func in dir(foyer.forcefields) if 'load' in func and '__' not in func]
      for func in dir(foyer.forcefields):
          if 'load_' in func and '__' not in func:
              eval('foyer.forcefields.' + func)()
  
  
  def test_load_forcefield():
      OPLSAA = foyer.forcefields.get_forcefield(name='oplsaa')
      TRAPPE_UA = foyer.forcefields.get_forcefield(name='trappe-ua')
      with pytest.raises(ValueError):
          foyer.forcefields.get_forcefield('bogus_name')
  