ExpressionEvaluatorImpl implements ExpressionEvaluator { private boolean evaluateLiteralBooleanExpression(LiteralBooleanExpression literalBooleanExpression) { return literalBooleanExpression != null && literalBooleanExpression.getLiteral(); }  @Override Map<String, Set<String>> getColumnNames(Object expression); @Override T evaluate(Object expression, DataRow dataRow); @Override T evaluateAs(Object expression, DataRow dataRow, Class<T> cls);  }
@Test public void testEvaluateLiteralBooleanExpression() { assertThat(bool(true), is(true)); assertThat(bool(false), is(false)); }