Request:
POST /api/adwords/reportdownload/v201702 HTTP/1.1
User-Agent: Test App (AwApi-PHP, googleads-php-lib/25.0.0, PHP/5.5.9, GuzzleHttp/6.0.0, curl/7.52.0)
Content-Type: application/x-www-form-urlencoded
Host: adwords.google.com
Authorization: Bearer 123.abc.456.xyz
developerToken: ABcdeFGH93KL-NOPQ_STUv
clientCustomerId: 111-222-3333
skipReportHeader: false
skipColumnHeader: false
skipReportSummary: false
useRawEnumValues: true
includeZeroImpressions: false

__rdxml=<?xml version="1.0"?>
<reportDefinition><selector><fields>CampaignId</fields><fields>AdGroupId</fields><fields>Id</fields><fields>Criteria</fields><fields>CriteriaType</fields><fields>Impressions</fields><fields>Clicks</fields><fields>Cost</fields><predicates><field>Status</field><operator>NOT_IN</operator><values>PAUSED</values></predicates></selector><reportName>Criteria performance report #58ec957f1d8f7</reportName><reportType>CRITERIA_PERFORMANCE_REPORT</reportType><dateRangeType>LAST_7_DAYS</dateRangeType><downloadFormat>CSV</downloadFormat></reportDefinition>

Response:
HTTP/1.1 200 OK

"CRITERIA_PERFORMANCE_REPORT (Apr 4, 2017-Apr 10, 2017)"
Campaign ID,Ad group ID,Keyword ID,Keyword / Placement,Criteria Type,Impressions,Clicks,Cost
11111,33333,3000000,Content,KEYWORD,1,2,200000
2222,44444,300,Parent,PARENT,1,2,700000
5555,66666,3000000,Content,KEYWORD,1,2,100000
Total, --, --, --, --,3,6,1000000

--------
Error:
NULL