def evidence(var, e, outcomeSpace):
    """
    argument
    `var`, a valid variable identifier.
    `e`, the observed value for var.
    `outcomeSpace`, dictionary with the domain of each variable

    Returns dictionary with a copy of outcomeSpace with var = e
    """
    newOutcomeSpace = outcomeSpace.copy()  # Make a copy of outcomeSpace with a copy to method copy(). 1 line
    newOutcomeSpace[var] = (e,)  # Replace the domain of variable var with a tuple with a single element e. 1 line
    return newOutcomeSpace