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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 from_str(cls, string):
 """ Creates a clause from a given string. Parameters string: str A string of the form `a+!b` which translates to `a AND NOT b`. Returns ------- caspo.core.clause.Clause Created object instance """

        return cls([Literal.from_str(lit) for lit in string.split('+')])