@throws nullpointerexception if the input parameter is null
@see buffer
@return the given reader or a new {@link bufferedreader} for the given reader
@param reader the reader to wrap or return (not null)
@description returns the given reader if it is a {@link bufferedreader}, otherwise creates a bufferedreader from the givenreader.
file : https_github_com_apache_commons-io_git/src/main/java/org/apache/commons/io/IOUtils.java