Define the FLE2RangeIndexedValueV2 payload type in the EncryptedBinDataType enum in fle_field_schema.idl. Then, create the class FLE2IndexedRangeEncryptedValueV2 which implements the parseAndDecrypt() and serialize() methods.

The serialize method shall output the binary string that can be parsed as:

index_key_id (16) || bson_type (1) || SKE.Enc(serverToken, ciphertext) || encrypted_counters_and_tags

where encrypted_counters_and_tags can be further parsed as:

[ ( SKE.Enc(FS[ f, 2, e, 1 ], (e.counter || contentionFactor)) || e.tag || SKE.Enc(FS[ f, 2, e, 2 ], 0128) ) ] for each e in payload.edgeTokenSet