question: void close ( ) throws IOException ;
target:  Closes the reader iff it is open. <p> Note: Closing a reader does not have a side-effect on any open reader or writer for the same file. Specifically, if two readers are open for the same file and one is closed, then other will remain open. Likewise, if a reader is open for the live HALog file, closing the writer will not close the reader and closing the reader will not close the writer.