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#  or more contributor license agreements.  See the NOTICE file
#  distributed with this work for additional information
#  regarding copyright ownership.  The ASF licenses this file
#  to you under the Apache License, Version 2.0 (the
#  "License"); you may not use this file except in compliance
#  with the License.  You may obtain a copy of the License at
#  
#    http://www.apache.org/licenses/LICENSE-2.0
#    
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def get(r, item, accum, transform, init, l):
    iv = item.get(r)
    av = accum.get(r)

    def tfun(a, i):
        return transform.get(((av, a), (iv, i)) + r)

    lv = l.get(r)
    return reduce(tfun, () if lv is None else lv, init.get(r))