Get php code when I export cdrs records without any record

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<h4>A PHP Error was encountered</h4>

<p>Severity: Notice</p>
<p>Message: Undefined variable: customer_array</p>
<p>Filename: controllers/reports.php</p>
<p>Line Number: 317</p>

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<h4>A PHP Error was encountered</h4>

<p>Severity: Warning</p>
<p>Message: Invalid argument supplied for foreach()</p>
<p>Filename: helpers/csv_helper.php</p>
<p>Line Number: 37</p>

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