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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 to_wire_dict (self):
 """Return a simplified transport object for logging and caching. The transport object must contain these attributes: - url_data.valid: bool Indicates if URL is valid - url_data.result: unicode Result string - url_data.warnings: list of tuples (tag, warning message) List of tagged warnings for this URL. - url_data.name: unicode string or None name of URL (eg. filename or link name) - url_data.parent_url: unicode or None Parent URL - url_data.base_ref: unicode HTML base reference URL of parent - url_data.url: unicode Fully qualified URL. - url_data.domain: unicode URL domain part. - url_data.checktime: int Number of seconds needed to check this link, default: zero. - url_data.dltime: int Number of seconds needed to download URL content, default: -1 - url_data.size: int Size of downloaded URL content, default: -1 - url_data.info: list of unicode Additional information about this URL. - url_data.line: int Line number of this URL at parent document, or -1 - url_data.column: int Column number of this URL at parent document, or -1 - url_data.page: int Page number of this URL at parent document, or -1 - url_data.cache_url: unicode Cache url for this URL. - url_data.content_type: unicode MIME content type for URL content. - url_data.level: int Recursion level until reaching this URL from start URL - url_data.last_modified: datetime Last modification date of retrieved page (or None). """

        return dict(valid=self.valid,
          extern=self.extern[0],
          result=self.result,
          warnings=self.warnings[:],
          name=self.name or u"",
          title=self.get_title(),
          parent_url=self.parent_url or u"",
          base_ref=self.base_ref or u"",
          base_url=self.base_url or u"",
          url=self.url or u"",
          domain=(self.urlparts[1] if self.urlparts else u""),
          checktime=self.checktime,
          dltime=self.dltime,
          size=self.size,
          info=self.info,
          line=self.line,
          column=self.column,
          page=self.page,
          cache_url=self.cache_url,
          content_type=self.content_type,
          level=self.recursion_level,
          modified=self.modified,
        )