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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 is_binary(system_binary_str):
    '''Assert that a string represents a system binary

    Return true if a string represents a system binary
    Raise TypeError if the system_binary_str is not a string
    Raise ValueError if the system_binary_str is not a system binary

    :param system_binary_str: STR string representing a system binary
    '''
    if not isinstance(system_binary_str, str):
        raise TypeError("{} must be of type STR".format(system_binary_str))
    binary_str = shutil.which(system_binary_str)
    if not binary_str:
        msg = "{} is not valid system binary".format(system_binary_str)
        raise ValueError(msg)
    return True