anchor.diff:  sudo apt-get install protobuf-compiler sudo apt-get install protobuf-compiler
   ----
   
  -[[concepts]]
  -Concepts
  -~~~~~~~~
  -
  -[[exported_variables]]
  -Exported Variables
  -^^^^^^^^^^^^^^^^^^
  +# Concepts
  +
  +## Exported Variables
   
   The variables exported by the CMake protobuf package and used in this example include:
   
  
positive.code:   * CMakeLists.txt - Contains the CMake commands you wish to run
    * main.cpp - The source file from the protobuf example.
  
  [[requirements]]
  Requirements
  ~~~~~~~~~~~~
  
  This example requires the protocol buffers binary and libraries to be installed.
  
  
negative.code: More variables are defined and can be found by examining the documentation at the
  top of your `FindProtobuf.cmake` file.
  
  ## Generating Source
  
  The protobuf CMake package includes a number of helper functions to make the
  code generation easier. In this example we are generating C++ source and use
  