class Sprockets::Deprecation

def extract_callstack
  return _extract_callstack if callstack.first.is_a? String
  offending_line = callstack.find { |frame|
    frame.absolute_path && !ignored_callstack(frame.absolute_path)
  } || callstack.first
  [offending_line.path, offending_line.lineno, offending_line.label]
end