lib/util/common.js
function setResponseHeaders(res) {
  if(res.setHeader) {
    var contentType = res.getHeader('content-type');
    if (!contentType) {
      res.setHeader('Content-Type', 'application/json');
    }
  }
}
function setResponseHeaders(res) {
  if(res.setHeader) {
    var contentType = res.getHeader('content-type');
    if (!contentType) {
      res.setHeader('Content-Type', 'application/json');
    }
  }
}
function setResponseHeaders ( res ) { if ( res . setHeader ) { var contentType = res . getHeader ( 'content-type' ) ; if ( ! contentType ) { res . setHeader ( 'Content-Type' , 'application/json' ) ; } } }
set default response headers
set default response headers