code: static StructTypeInfo getSchemaTypeInfo(Configuration conf) {
      String schemaTypeInfo = conf.get(SCHEMA_TYPE_INFO);
      if (schemaTypeInfo != null && !schemaTypeInfo.isEmpty()) {
        LOG.debug("Got schema typeInfo from conf: {}", schemaTypeInfo);
        return (StructTypeInfo) TypeInfoUtils.getTypeInfoFromTypeString(conf.get(SCHEMA_TYPE_INFO));
      }
      return null;
    }
docs: Gets the StructTypeInfo that declares the total schema of the file from the configuration