try {
XContentBuilder builder = XContentFactory.contentBuilder(XContentType.JSON);
builder.startObject();
fieldMapper.toXContent(builder, includeDefaults ? includeDefaultsParams : ToXContent.EMPTY_PARAMS);
builder.endObject();
fieldMappings.put(field, new FieldMappingMetaData(fieldMapper.names().fullName(), builder.bytes()));
} catch (IOException e) {
throw new ElasticsearchException("failed to serialize XContent of field [" + field + "]", e);
}
}