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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 pod_present(
        name,
        namespace='default',
        metadata=None,
        spec=None,
        source='',
        template='',
        **kwargs):
    '''
    Ensures that the named pod is present inside of the specified
    namespace with the given metadata and spec.
    If the pod exists it will be replaced.

    name
        The name of the pod.

    namespace
        The namespace holding the pod. The 'default' one is going to be
        used unless a different one is specified.

    metadata
        The metadata of the pod object.

    spec
        The spec of the pod object.

    source
        A file containing the definition of the pod (metadata and
        spec) in the official kubernetes format.

    template
        Template engine to be used to render the source file.
    '''
    ret = {'name': name,
           'changes': {},
           'result': False,
           'comment': ''}

    if (metadata or spec) and source:
        return _error(
            ret,
            '\'source\' cannot be used in combination with \'metadata\' or '
            '\'spec\''
        )

    if metadata is None:
        metadata = {}

    if spec is None:
        spec = {}

    pod = __salt__['kubernetes.show_pod'](name, namespace, **kwargs)

    if pod is None:
        if __opts__['test']:
            ret['result'] = None
            ret['comment'] = 'The pod is going to be created'
            return ret
        res = __salt__['kubernetes.create_pod'](name=name,
                                                namespace=namespace,
                                                metadata=metadata,
                                                spec=spec,
                                                source=source,
                                                template=template,
                                                saltenv=__env__,
                                                **kwargs)
        ret['changes']['{0}.{1}'.format(namespace, name)] = {
            'old': {},
            'new': res}
    else:
        if __opts__['test']:
            ret['result'] = None
            return ret

        # TODO: fix replace_namespaced_pod validation issues
        ret['comment'] = 'salt is currently unable to replace a pod without ' \
            'deleting it. Please perform the removal of the pod requiring ' \
            'the \'pod_absent\' state if this is the desired behaviour.'
        ret['result'] = False
        return ret

    ret['changes'] = {
        'metadata': metadata,
        'spec': spec
    }
    ret['result'] = True
    return ret