question: public String toString ( ) { StringBuilder sb = new StringBuilder ( ) ; long time = startTime ; for ( int row = 0 ; row < rows ; row ++ , time += step ) { sb . append ( time ) ; sb . append ( ": " ) ; for ( int ds = 0 ; ds < dsCount ; ds ++ ) { sb . append ( data [ row ] [ ds ] ) ; sb . append ( " " ) ; } sb . append ( NEWLINE ) ; } return sb . toString ( ) ; }
target:  Returns a summary of the contents of this data chunk. The first column is the time (RRD format) and the following columns are the data source values.