public WriterOptions setSchema(TypeDescription schema) {
      if (schema != null) {
        this.explicitSchema = true;
        super.setSchema(schema);
      }
      return this;
    }
Set the schema for the file. This is a required parameter.
@param schema the schema for the file.
@return this
ql/src/java/org/apache/hadoop/hive/ql/io/orc/OrcFile.java