anchor.diff:  
   URI parameters can be added to every URI action mapper regardless of their type. In this section we want to build an action mapper tree which can interpret the following URI fragment:
   
  -    #!/products/id/4711/details
  -	
  +    #!products/id/4711/details
  +    
   In this example, we have a single-valued parameter of type Integer with the parameter name `id`. We can build the action mapper tree as follows:
   
   [source,java]
  
positive.code: 
  In this section, we will build a mapper tree which is able to handle the following URI fragment:
  
      #!/helloWorld
  	
  When the user visits this fragment, we want to print `Hello World!` to the console. To do this, we need two things: we have to define an action class and the URI action mapper tree which can resolves this URI fragment to this action class.
  
  Let's first define the action class:
  
negative.code: Now we have a good starting point from which we can go on. We will expand our mapper tree with more mappers in the next step. Let us define the following three top-level path segments which can be handled by the mapper tree:
  
  ....
  #!user
  #!admin
  #!settings
  ....
  
  We can do this in the same way as we did above, except that we continue building the mapper tree after we have fully configured the first action mapper:
  