question: private List extractColumnKeys ( String line ) { List keys = new java . util . ArrayList ( ) ; int fieldIndex = 0 ; int start = 0 ; for ( int i = 0 ; i < line . length ( ) ; i ++ ) { if ( line . charAt ( i ) == this . fieldDelimiter ) { if ( fieldIndex > 0 ) { String key = line . substring ( start , i ) ; keys . add ( removeStringDelimiters ( key ) ) ; } start = i + 1 ; fieldIndex ++ ; } } String key = line . substring ( start , line . length ( ) ) ; keys . add ( removeStringDelimiters ( key ) ) ; return keys ; }
target:  Extracts the column keys from a string.