title: how to generate the report query without using the dimesion attribute for google DFP ad exchange API
body: <p>I am trying generate the report by using only Dimension and columns (excluding Dimension Attribute ) For the DFP_API ad_exchange there is no Dimension Attribute for my requirement . Please help me out in generating the report .Please find the below report query </p>
  
  <pre><code>report_job = {
        'report_Query': {
            'dimensions': ['AD_EXCHANGE_AGENCY'],
  
            'statement': filter_statement,
            'columns': ['AD_EXCHANGE_INVENTORY_SIZE', 'AD_EXCHANGE_URL_ID'],
            'dateRangeType': 'CUSTOM_DATE',
            'startDate': start_date,
            'endDate': end_date
        }
    }
  </code></pre>