public CompletionProposal withSeparateTokens(String suffix,String explanation){
  return new CompletionProposal((start.endsWith(" ") || start.isEmpty()) ? start + suffix : start + " " + suffix,explanation);
}

public CompletionProposal withSeparateTokens ( String suffix , String explanation ) { return new CompletionProposal ( ( start . endsWith ( " " ) || start . isEmpty ( ) ) ? start + suffix : start + " " + suffix , explanation ) ; }
add a suffix as a new token , that is , make sure there is a space before it . a space is not appended if this is the very first token .
