<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _GetStructureValue(self, structure, key):
 """Retrieves a value from a parsed log line, removing empty results. Args: structure (pyparsing.ParseResults):
 parsed log line. key (str):
 results key to retrieve from the parsed log line. Returns: type or None: the value of the named key in the parsed log line, or None if the value is a ParseResults object. """

    value = structure.get(key)
    return value if not isinstance(value, pyparsing.ParseResults) else None