class SimpleCov::SourceFile

def covered_percent
  return 100.0 if lines.length == 0 or lines.length == never_lines.count
  relevant_lines = lines.count - never_lines.count - skipped_lines.count
  if relevant_lines == 0
    0.0
  else
    Float((covered_lines.count) * 100.0 / relevant_lines.to_f)
  end
end