<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _set_textarea(el, value):
 """ Set content of given textarea element `el` to `value`. Args: el (obj):
 Reference to textarea element you wish to set. value (obj/list):
 Value to which the `el` will be set. """

        if isinstance(value, dict):
            el.text = value["val"]
        elif type(value) in [list, tuple]:
            el.text = "\n\n".join(
                "-- %s --\n%s" % (item["source"], item["val"])
                for item in value
            )
        else:
            el.text = value