anchor.diff:  %% The arguments are as follows:
   %%
   %% + `Value'
  -%%     <br/>The value to integrate.
  -%% 
  -%% + `State'
  -%%     <br/>The probe state, originally returned by `probe_init/3' and subsequentially
  +%%     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>
   %% 
  -%% Retrieve one or more data points from the probe.
  +%% 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'
  -%%     <br/>List of data point atoms to retrieve values for.
  -%% 
  -%% + `State'
  -%%     <br/>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 implementation of this function shall return the value of all
  -%% data points provided in `DataPoints', given that they are supported.
  +%%     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:
   %%
  
positive.code: %%  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.
  %%
  %%  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)'.
  %%
  %%  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 following functions are to be implemented and exported by a probe
  %% implementation.
  
negative.code: %%   file, You can obtain one at http://mozilla.org/MPL/2.0/.
  %%
  %% -------------------------------------------------------------------
  %% @doc Interface library for managing probes.<br/>
  %%
  %%  This library contains the main API for accessing all probes
  %%  executing in exometer.
  