# File lib/asciidoctor/path_resolver.rb, line 141
  def is_root? path
    # Unix absolute paths and UNC paths start with slash
    if path.start_with? SLASH
      true
    # Windows roots can begin with drive letter
    elsif @file_separator == BACKSLASH && WindowsRootRx =~ path
      true
    # Absolute paths in the browser start with file:///
    elsif ::RUBY_ENGINE_OPAL && ::JAVASCRIPT_PLATFORM == 'browser' && (path.start_with? 'file:///')
      true
    else
      false
    end
  end