class Byebug::BreakCommand

def valid_breakpoints_for(path, line)
  potential_lines = Breakpoint.potential_lines(path)
  annotator = ->(n) { potential_lines.include?(n) ? "[B]" : "   " }
  source_file_formatter = SourceFileFormatter.new(path, annotator)
  source_file_formatter.lines_around(line).join.chomp
end