• To modify the CallerCalleeProcessor to include other types of symbols, it may be necessary to extend the Symbol class with custom behavior for each new type of symbol. This would require modifications to the parsing logic and the graph generation logic. You would also have to upgrade the process function to handle these new symbols, and possibly write new helper methods to handle their particular features.

• Optimization of the CallerCalleeProcessor for larger projects could involve a number of strategies. Firstly, it could involve subsetting the graph and processing smaller pieces in parallel, i.e., using a divide and conquer strategy. Secondly, data structures used in the implementation could be re-evaluated to ensure that they’re the most efficient for the task at hand. Thirdly, some level of caching could be introduced to prevent re-processing of symbols that have already been accounted for. Lastly, one might look into lazy evaluation techniques, where the caller-callee relationships are only computed as necessary for the specific task at hand.