public void TryGetFirst_WithNonEmptyEnumerableAndContradictionalLambda_ExpectsFalse()
 => False(ENMRBL_EMPTY.TryGetFirst(DefaultDelegates.ContradictionalLambda <MultiItems>(), out _));
 public void TryGetFirst_WithEmptyEnumerable_ExpectsFalse()
 => False(ENMRBL_EMPTY.TryGetFirst(DefaultDelegates.TautologicalLambda <MultiItems>(), out _));