@Override
    public Builder toBuilder() {
        return new Builder()
                .sourceLocation(getSourceLocation())
                .partitionSpecialCases(partitionSpecialCases)
                .regionSpecialCases(regionSpecialCases);
    }
Gets the map of partition string to a list of region special cases defined in the trait.

@return Returns a map of region string to a list of {@link RegionSpecialCase}
smithy-aws-endpoints/src/main/java/software/amazon/smithy/rulesengine/aws/traits/StandardRegionalEndpointsTrait.java