Check whether the current connection can connect with the target connection.
canConnect(a: Connection | null, b: Connection | null, isDragging: boolean, opt_distance?: number): boolean;
|a||Connection | null||Connection to check compatibility with.|
|b||Connection | null||Connection to check compatibility with.|
|isDragging||boolean||True if the connection is being made by dragging a block.|
|opt_distance||number||(Optional) The max allowable distance between the connections for drag checks.|
Whether the connection is legal.