<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _maybe_coerce_values(self, values):
 """Unbox to an extension array. This will unbox an ExtensionArray stored in an Index or Series. ExtensionArrays pass through. No dtype coercion is done. Parameters values : Index, Series, ExtensionArray Returns ------- ExtensionArray """

        if isinstance(values, (ABCIndexClass, ABCSeries)):
            values = values._values
        return values