public SchemaMapping fromParquet(MessageType parquetSchema) {
    List<Type> fields = parquetSchema.getFields();
    List<TypeMapping> mappings = fromParquet(fields);
    List<Field> arrowFields = fields(mappings);
    return new SchemaMapping(new Schema(arrowFields), parquetSchema, mappings);
  }
@Test
  public void testParquetMapToArrow() {
    GroupType mapType = Types.requiredMap().key(INT32).optionalValue(INT64).named("myMap");
    MessageType parquet = Types.buildMessage().addField(mapType).named("root");
    Schema expected = new Schema(asList(field(
        "myMap",
        new ArrowType.Map(false),
        field(null, false, new ArrowType.Int(32, true)),
        field(null, true, new ArrowType.Int(64, true)))));
    SchemaMapping mapping = converter.fromParquet(parquet);
    Schema actual = mapping.getArrowSchema();

    Assert.assertEquals(expected, actual);
  }