code: def cp (from, to, as: user, on: hosts, quiet: false, once: nil)
        self.once once, quiet: quiet do
          log.info "cp: #{from} -> #{to}", quiet: quiet do
            Dir.chdir File.dirname(file) do
              hash_map(hosts) do |host|
                host.cp from, to, as: as, quiet: quiet
              end
            end
          end
        end
      end
docs: Copy a file or readable to the host filesystems.
   @overload cp(readable, to, as: user, on: hosts, quiet: false)
     @param [#read] from An object from which to read the contents of the new file.
     @param [String] to The file name to write the string to.
     @macro onable
     @macro asable
     @macro quietable
     @macro onceable
   @overload cp(filename, to, as: user, on: hosts, quiet: false)
     @param [String] from The name of the local file to copy.
     @param [String] to The file name to write the string to.
     @macro onable
     @macro asable
     @macro quietable
     @macro onceable