code: function extractOriginHeaders_(headers) {
      const result = {
        isSameOrigin: false,
      };
      for (const key in headers) {
        if (headers.hasOwnProperty(key)) {
          const normalizedKey = key.toLowerCase();
          // for same-origin requests where the Origin header is missing, AMP sets the amp-same-origin header
          if (normalizedKey === 'amp-same-origin') {
            result.isSameOrigin = true;
            return result;
          }
          // use the origin header otherwise
          if (normalizedKey === 'origin') {
            result.origin = headers[key];
            return result;
          }
        }
      }
      return null;
    }
docs: Extracts the `AMP-Same-Origin` and `Origin` header values.
  
  @param {Object} headers
  @returns {Object} object containing the origin or isSameOrigin value
  @private