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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 pull_dependencies(self, nodes):
 """Pull all the dependencies."""

        visitor = DependencyFinderVisitor()
        for node in nodes:
            visitor.visit(node)
        for dependency in 'filters', 'tests':
            mapping = getattr(self, dependency)
            for name in getattr(visitor, dependency):
                if name not in mapping:
                    mapping[name] = self.temporary_identifier()
                self.writeline('%s = environment.%s[%r]' %
                               (mapping[name], dependency, name))