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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 add_debugged_source_file(self, debugged_source_file):
 """Add a DebuggedSourceFile proto."""

    # TODO(cais): Should the key include a host name, for certain distributed
    #   cases?
    key = debugged_source_file.file_path
    self._source_file_host[key] = debugged_source_file.host
    self._source_file_last_modified[key] = debugged_source_file.last_modified
    self._source_file_bytes[key] = debugged_source_file.bytes
    self._source_file_content[key] = debugged_source_file.lines