public String getImplicitGlobalRegion() {
        return implicitGlobalRegion;
    }
Gets this partition's implicit global region: the region that
non-regionalized (global) services should use for signing.

@return returns the partition's implicit global region.
smithy-aws-endpoints/src/main/java/software/amazon/smithy/rulesengine/aws/language/functions/partition/PartitionOutputs.java