\brief Retrieve the completion string associated with a particular chunk within a completion string.
\param completion_string the completion string to query.
\param chunk_number the 0-based index of the chunk in the completion string.
\returns the completion string associated with the chunk at index \c chunk_number.
See Implementation
\brief Retrieve the completion string associated with a particular chunk within a completion string.
\param completion_string the completion string to query.
\param chunk_number the 0-based index of the chunk in the completion string.
\returns the completion string associated with the chunk at index \c chunk_number.