test/org/apache/pig/builtin/avro/data/json/recordsOfArraysOfRecords.json

{"key" : "A",
 "values" : [
    {"k" : "a", "v" : 1}
 ]
}
{"key" : "B",
 "values" : []
}
{"key" : "C",
 "values" : [
    {"k" : "c", "v" : 3},
    {"k" : "c1", "v" : 4},
    {"k" : "c2", "v" : 5}
 ]
}