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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 params_for(prefix, kwargs):
 """Extract parameters that belong to a given sklearn module prefix from ``kwargs``. This is useful to obtain parameters that belong to a submodule. Examples -------- {'a': 3, 'b': 4} """

    if not prefix.endswith('__'):
        prefix += '__'
    return {key[len(prefix):]: val for key, val in kwargs.items()
            if key.startswith(prefix)}