### Question:
MathematicalFunction { private static FunctionResolver radians() { return FunctionDSL.define(BuiltinFunctionName.RADIANS.getName(), ExprCoreType.numberTypes().stream() .map(type -> FunctionDSL.impl(FunctionDSL.nullMissingHandling( v -> new ExprDoubleValue(Math.toRadians(v.doubleValue()))), DOUBLE, type)).collect(Collectors.toList())); }  static void register(BuiltinFunctionRepository repository);  }### Answer:
@Test public void radians_null_value() { FunctionExpression radians = dsl.radians(DSL.ref(DOUBLE_TYPE_NULL_VALUE_FIELD, DOUBLE)); assertEquals(DOUBLE, radians.type()); assertTrue(radians.valueOf(valueEnv()).isNull()); }
@Test public void radians_missing_value() { FunctionExpression radians = dsl.radians(DSL.ref(DOUBLE_TYPE_MISSING_VALUE_FIELD, DOUBLE)); assertEquals(DOUBLE, radians.type()); assertTrue(radians.valueOf(valueEnv()).isMissing()); }