public static boolean isNumber(Class<?> clazz) {
        if ( clazz == null ) {
            return false;
        }
        else {
            return NUMBER_TYPES.contains( clazz );
        }
    }
@Test
    public void testIsNumber() {
        assertFalse( NativeTypes.isNumber( null ) );
        assertFalse( NativeTypes.isNumber( Object.class ) );
        assertFalse( NativeTypes.isNumber( String.class ) );

        assertTrue( NativeTypes.isNumber( double.class ) );
        assertTrue( NativeTypes.isNumber( Double.class ) );
        assertTrue( NativeTypes.isNumber( long.class ) );
        assertTrue( NativeTypes.isNumber( Long.class ) );
        assertTrue( NativeTypes.isNumber( BigDecimal.class ) );
        assertTrue( NativeTypes.isNumber( BigInteger.class ) );
    }