@Test
public void isExpression() throws Exception {

    assertFalse(Expression.isExpression(null));
    assertFalse(Expression.isExpression(""));
    assertFalse(Expression.isExpression("   "));
    assertFalse(Expression.isExpression("foo"));
    assertTrue(Expression.isExpression("${foo}"));
    assertTrue(Expression.isExpression("${foo}/bar"));
    assertTrue(Expression.isExpression("my/${foo}/bar"));
}