class SimpleCov::Formatter::Base

turn reflects what the user enabled).
insertion order as `SourceFile#coverage_statistics`, which in
order of `result.coverage_statistics` (which is the same
to Y") is always first; per-criterion lines follow in the
measured. The header line ("Coverage report generated for X
Emit one summary line per criterion that the run actually

def output_message(result)
  header = "#{message_prefix}Coverage report generated for #{result.command_name} to #{displayable_output_path}"
  body   = result.coverage_statistics.filter_map { |criterion, stat| stats_line(criterion, stat) }
  [header, *body].join("\n")
end