Add chunked-pmap again, via delays.
Add chunked-pmap again, via delays.

acthp/ucsc-xena-server,ucscXena/ucsc-xena-server,acthp/ucsc-xena-server,ucscXena/ucsc-xena-server,acthp/ucsc-xena-server,ucscXena/ucsc-xena-server,acthp/ucsc-xena-server,ucscXena/ucsc-xena-server,ucscXena/ucsc-xena-server,acthp/ucsc-xena-server