anchor.diff:  `RegisterRequestData`
     
   ==== +HTTP POST+
  -
  -===== Query parameters
  -*filter*=[string[,string ...]]::
  -  (_optional_)
  -  When set, filter the properties returned by the names in the filter string.
  -
   Completes the registration, storing a new device associated with the user.
   
   ===== Client request body
  
positive.code: _https://example.com/johndoe/0f0f0f0f0f...0f_
  
  ==== +HTTP GET+
  Returns properties for the device, optionally filtered.
  
  ===== Query parameters
  *filter*=[string[,string ...]]::
    (_optional_)
    When set, filter the properties returned by the names in the filter string.
  
  ===== Server Response
  `DeviceDescriptor`
  
  ==== +HTTP POST+
  Sets properties for the device, then returns the devices new properties,
  optionally filtered.
  
  ===== Query parameters
  *filter*=[string[,string ...]]::
    (_optional_)
    When set, filter the properties returned by the names in the filter string.
  
  ===== Client Request
  `Dictionary`
  
negative.code: _https://example.com/johndoe_
  
  ==== +HTTP GET+
  Returns a list of device handles, with their properties.
  
  ===== Server response
  `DeviceDescriptor[]`
  