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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def iter_processes(self, proc_filter=None):
 """Yields processes from psutil.process_iter with an optional filter and swallows psutil errors. If a psutil exception is raised during execution of the filter, that process will not be yielded but subsequent processes will. On the other hand, if psutil.process_iter raises an exception, no more processes will be yielded. """

    with swallow_psutil_exceptions():  # process_iter may raise
      for proc in psutil.process_iter():
        with swallow_psutil_exceptions():  # proc_filter may raise
          if (proc_filter is None) or proc_filter(proc):
            yield proc