{
    "first_name":   { "length_equal": 2 },
    "last_name":    { "length_equal": [7] },
    "middle_name": [{ "length_equal": [3] }],
    "empty_name":   { "length_equal": 3 },

    "value_is_hash":        { "length_equal": 2 },
    "value_is_empty_hash":  { "length_equal": 2 },
    "value_is_array":       { "length_equal": 2 },
    "value_is_empty_array": { "length_equal": 2 }
}