{
"field1": { "equal_to_field": "field2" },
"field2": { "equal_to_field": ["field1"] },
"field3": { "equal_to_field": ["field1"] },
"empty_field": { "equal_to_field": "field2" }
}
{
"field1": { "equal_to_field": "field2" },
"field2": { "equal_to_field": ["field1"] },
"field3": { "equal_to_field": ["field1"] },
"empty_field": { "equal_to_field": "field2" }
}