private static TypeInfo generateArrayTypeInfo(Schema schema,
      Set<Schema> seenSchemas) throws AvroSerdeException {
    assert schema.getType().equals(Schema.Type.ARRAY);
    Schema itemsType = schema.getElementType();
    TypeInfo itemsTypeInfo = generateTypeInfo(itemsType, seenSchemas);

    return TypeInfoFactory.getListTypeInfo(itemsTypeInfo);
  }
Generate a TypeInfo for an Avro Map.  This is made slightly simpler in that
Avro only allows maps with strings for keys.
serde/src/java/org/apache/hadoop/hive/serde2/avro/SchemaToTypeInfo.java