anchor.diff:  %%  blocking, an `exometer_entry' implementation can be used instead
   %%  to do the gathering in-process.
   %%  
  -%%  A probe is created throgh the `new' call, which will spawn a new process
  -%%  and invoke the argument-provided implementation of `exometer_probe'.
  -%%  While the process is not a gen_server, it behaves similarly and provides
  -%%  a state to all implementation calls.
  +%%  A probe is created throgh the `exomter_probe:new/3' call, which in
  +%%  its turn is called by `exometer:new/3'. During probe creation, a
  +%%  new process is spawned to handle the probe and call its
  +%%  implementation.  While the created process is not a gen_server, it
  +%%  behaves similarly and provides a state to all implementation
  +%%  calls.
   %%
   %%  Once running, the probe collects data from a subsystem, such as
   %%  `/proc', `sysfs', and `netlink', through timer-based calls to
   %%  `probe_sample/1' or explicit calls to `probe_update/2'.
   %%
  -%%  The probe is free to setup any number of data points, where each
  -%%  data point is a specifric sample from the probe. For example, a
  -%%  probe that measures network traffic would have `rx_packets',
  -%%  `tx_packets', `errors', `dropped', and other data points reported
  -%%  by `ifconfig(8)' and `ip(8)'.
  +%%  A probe implementation can support any number of data points,
  +%%  where each data point is a specifric sample from the probe. For
  +%%  example, a probe that measures network traffic would have
  +%%  `rx_packets', `tx_packets', `errors', `dropped', and other data
  +%%  points reported by `ifconfig(8)' and `ip(8)'.
   %%
   %%  Values are retrieved from the probe through the `probe_get_value/2'
   %%  call, which specifies the data points to be returned. The probe is
   %%  expected to gather the given data points and return them to the
   %%  caller.
   %% 
  -%% The probe callback interface
  +%% == The probe callback interface ==
   %%
   %% The following functions are to be implemented and exported by a probe
   %% implementation.
  
positive.code: %% <pre lang="erlang">
  %%      probe_init(Name, Type, Options)</pre>
  %% 
  %% The custom probe shall create the necessary state for the new metric and return
  %% it for furure access through `probe_update/2' and `get_value/2' calls. 
  %% 
  %% The arguments are as follows:
  %%
  %% + `Name'
  %%     <br/>Specifies the name of the metric to be created as a list of atoms. 
  %% 
  %% + `Type'
  %%     <br/>Specifies the type provided to the `exometer:new/3' call (before it
  %%     was translated by the type - exometer probe map). It can be used if several
  %%     different types are mapped to the same probe module.
  %% 
  %% + `Options'
  %%     <br/>Specifies an option list that contains additional setup directives to
  %%     the probe. The actual options to support are a combination of the 
  %%     standard options, described below, and probe specific options
  %%     processed by `probe_init/3'.
  
negative.code: %% The arguments are as follows:
  %%
  %% + `Value'
  %%     The value to integrate.
  %% 
  %% + `State'
  %%     The probe state, originally returned by `probe_init/3' and subsequentially
  %%     modified by other probe implementation calls.
  %% 
  %% This function can be called outside the periodic `probe_sample/1/'
  %% call to have the probe process a value given in `Value'.
  %%
  %% The `probe_update/2' implementation is invoked by `exometer:update/2', which
  %% calls `exometer_probe:update/4', which invokes the probe
  %% implementation.
  %%
  %% Once processed, `probe_update/2' shall return `{ok, NewState}',
  %% where `NewState' contains the new probe state with the processed
  %% value.
  %% 
  %%
  %% === probe_get_value/2 ===
  %% The `probe_get_value/2' function is invoked as follows:
  %% 
  %% <pre lang="erlang">
  %%      probe_get_value(DataPoints, State)</pre>
  %% 
  %% The `probe_get_value/2' implementation shall retrieve the value of
  %% one or more data points from the probe.
  %%
  %% The arguments are as follows:
  %%
  %% + `DataPoints'
  %%     List of data point atoms to retrieve values for.
  %% 
  %% + `State'
  %%     The probe state, originally returned by `probe_init/3' and subsequentially
  %%     modified by other probe implementation calls.
  %% 
  %% The `probe_get_value/2' implementation is invoked by
  %% `exometer:get_value/2', which calls `exometer_probe:get_value/4',
  %% which invokes the probe implementation.
  %% 
  %% If `exometer:get_value/2' is invoked with `default' as a single
  %% data point, the probe's `probe_get_datapoints/1' function will be
  %% called to retrieve all data points supported by the probe
  %% implementation. `probe_get_value/2' will then be called with the
  %% returned set of data points provided as an argument.
  %%
  %% This function shall return the value of all data points provided in
  %% `DataPoints', given that they are supported.
  %% 
  %% The list in the returned tuple shall have the format:
  %%
  