Function from_avro_datum_schemata 

pub fn from_avro_datum_schemata<R: Read>(
    writer_schema: &Schema,
    writer_schemata: Vec<&Schema>,
    reader: &mut R,
    reader_schema: Option<&Schema>,
) -> AvroResult<Value>

Decode a Value from raw Avro data.

If the writer schema is incomplete, i.e. contains Schema::Refs then it will use the provided schemata to resolve any dependencies.

When a reader Schema is provided, schema resolution will also be performed.