presto-main/src/main/java/io/prestosql/sql/relational/SqlToRowExpressionTranslator.java/Visitor/visitGenericLiteral
class Visitor:        @Override
        protected RowExpression visitGenericLiteral(GenericLiteral node, Void context)
        {
            Type type = getType(node);

            if (JSON.equals(type)) {
                return call(
                        metadata.resolveFunction(QualifiedName.of("json_parse"), fromTypes(VARCHAR)),
                        type,
                        constant(utf8Slice(node.getValue()), VARCHAR));
            }

            return call(
                    metadata.getCoercion(VARCHAR, type),
                    type,
                    constant(utf8Slice(node.getValue()), VARCHAR));
        }