anchor.diff:  
   Where `APP_HOME` is an OS environment.
   
  -[NOTE]
  -====
  -Some OS'es (such as Linux) do not support dashes in environment variable names,
  +NOTE: Some OS'es (such as Linux) do not support dashes in environment variable names,
   so here we are using `APP_HOME`. But if you specify `APP-HOME` then Camel 3 will automatic lookup
   the value as `APP_HOME` (with underscore) as fallback.
  -====
   
   You can have multiple placeholders in the same location, such as:
   
  
positive.code: a property with the key does not exists, eg `file.url:/some/path` where
  the default value is the text after the colon (eg /some/path).
  
  [NOTE]
  ====
  Do not use colon in the property key. The colon is used as a separator
  token when you are providing a default value.
  ====
  
  == Defining location
  
  
negative.code: </camelContext>
  ----
  
  NOTE: The location attribute (on propertyPlaceholder tag) is not mandatory
  
  Here we have a Camel XML route where we have defined the
  `<propertyPlaceholder>` to use a custom function, which we refer to be the
  