code: function ajaxHandleResponses( s, jqXHR, responses ) {
  
  	var contents = s.contents,
  		dataTypes = s.dataTypes,
  		responseFields = s.responseFields,
  		ct,
  		type,
  		finalDataType,
  		firstDataType;
  
  	// Fill responseXXX fields
  	for ( type in responseFields ) {
  		if ( type in responses ) {
  			jqXHR[ responseFields[type] ] = responses[ type ];
  		}
  	}
  
  	// Remove auto dataType and get content-type in the process
  	while( dataTypes[ 0 ] === "*" ) {
  		dataTypes.shift();
  		if ( ct === undefined ) {
  			ct = s.mimeType || jqXHR.getResponseHeader( "content-type" );
  		}
  	}
  
  	// Check if we're dealing with a known content-type
  	if ( ct ) {
  		for ( type in contents ) {
  			if ( contents[ type ] && contents[ type ].test( ct ) ) {
  				dataTypes.unshift( type );
  				break;
  			}
  		}
  	}
  
  	// Check to see if we have a response for the expected dataType
  	if ( dataTypes[ 0 ] in responses ) {
  		finalDataType = dataTypes[ 0 ];
  	} else {
  		// Try convertible dataTypes
  		for ( type in responses ) {
  			if ( !dataTypes[ 0 ] || s.converters[ type + " " + dataTypes[0] ] ) {
  				finalDataType = type;
  				break;
  			}
  			if ( !firstDataType ) {
  				firstDataType = type;
  			}
  		}
  		// Or just use first one
  		finalDataType = finalDataType || firstDataType;
  	}
  
  	// If we found a dataType
  	// We add the dataType to the list if needed
  	// and return the corresponding response
  	if ( finalDataType ) {
  		if ( finalDataType !== dataTypes[ 0 ] ) {
  			dataTypes.unshift( finalDataType );
  		}
  		return responses[ finalDataType ];
  	}
  }
docs: /* Handles responses to an ajax request:
  - sets all responseXXX fields accordingly
  - finds the right dataType (mediates between content-type and expected dataType)
  - returns the corresponding response