class Roda::RodaPlugins::PermissionsPolicy::Policy

def append_formatted_value(s, v)

Formats nested values, quoting strings and using :self and :src verbatim. 
def append_formatted_value(s, v)
  case v
  when String
    s << v.inspect << ' '
  when :self
    s << 'self '
  when :src
    s << 'src '
  else
    raise RodaError, "unsupported Permissions-Policy item value used: #{v.inspect}"
  end
end