[graph-tool] Freeze using SIRState

Hi everyone, I am conducting tests where I perform several parallel tests of the SIR model (they are not using n iterations because I need to find out when the model stabilizes, where si (t) = 0). Parallel execution has been carried out with the multiprocessing library. In larger networks (2000 nodes), when performing the procedure of removing parallel edges (the graphs are converted to undirected), the execution freeze. Can you imagine the reason for this behavior? If I don't execute the remove_parallel_edges function, everything happens normally ... Execution hangs when iterate_sync will be performed. A serial run works normally (without multiprocessing). Would anyone have a tip? Best regards, Ronaldo Alves