module Roda::RodaPlugins::ContentSecurityPolicy

def self.configure(app)

Yield the current Content Security Policy to the block. 
def self.configure(app)
  policy = app.opts[:content_security_policy] = if policy = app.opts[:content_security_policy]
    policy.dup
  else
    Policy.new
  end
  yield policy if block_given?
  policy.freeze
end