ns4.pge.com has no NS records.
NS records for this zone are defined at pge.com.
NS records for this zone are defined at pge.com.
Question and response
Question
dig ns4.pge.com. NS
Answer
The response has no answer records.
Authority
pge.com. 900 SOA ns0.pge.com. ibadmin.pge.com. 93489 3600 300 1814400 900
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0