anchor.diff:  %%   file, You can obtain one at http://mozilla.org/MPL/2.0/.
   %%
   %% -------------------------------------------------------------------
  -%% @doc Interface library for managing probes.
  +%% @doc Interface library for managing probes.<br/>
   %%
   %%  This library contains the main API for accessing all probes
   %%  executing in exometer.
  
positive.code:     delete/3,
      get_datapoints/3,
      get_value/3, get_value/4,
      update/4,o
      reset/3,
      sample/3,
      setopts/4
  
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:
  %%
  