code: function( offsideId ) {
  
                  // Look for an open Offside id
                  if ( openOffsidesId.length > 0 ) {
  
                      // Close matching Offside instance if an ID is provided
                      if ( !isNaN( offsideId ) ) {
  
                          instantiatedOffsides[ offsideId ].close();
                      } else {
  
                          // Close all Offside instances
                          openOffsidesId.forEach( function( offsideId ) {
                              instantiatedOffsides[ offsideId ].close();
                          });
                      }
  
                  }
              }
docs: Close all open Offsides. If an Offside instance id is provided, it just closes the matching instance instead