code: function makeHeaders(headers, params) {
          if (headers.length <= 0) {
              return params;
          }
  
          for (var prop in headers) {
              var head = headers[prop];
              prop = prop.replace(/-/, '_').toUpperCase();
              if (prop.indexOf('CONTENT_') < 0) {
                  // Quick hack for PHP, might be more or less headers.
                  prop = 'HTTP_' + prop;
              }
  
              params[params.length] = [prop, head]
          }
  
          return params;
      }
docs: Make headers for FPM
  
  Some headers have to be modified to fit the FPM
  handler and some others don't. For instance, the Content-Type
  header, when received, has to be made upper-case and the
  hyphen has to be made into an underscore. However, the Accept
  header has to be made uppercase, hyphens turned into underscores
  and the string "HTTP_" has to be appended to the header.
  
  @param  array headers An array of existing user headers from Node.js
  @param  array params  An array of pre-built headers set in serveFpm
  
  @return array         An array of complete headers.