code: @Nonnull
  	private static GenericDeclaration createGenericDeclaration(@Nonnull final String declaration) {
  		Check.notNull(declaration, "declaration");
  		return declaration.isEmpty() ? GenericDeclaration.UNDEFINED : GenericDeclaration.of(declaration);
  	}
docs: Creates a new instance of {@code GenericDeclaration} when the given declaration is not empty other wise it
  returns {@link GenericDeclaration#UNDEFINED}.
  
  @param declaration
  declaration of a generic
  @return instance of {@code GenericDeclaration} and never null