public PolicyFilter withPrincipal(EntityReference principal) {
        setPrincipal(principal);
        return this;
    }
<p>
Filters the output to only policies that reference the specified principal.
</p>

@param principal
       Filters the output to only policies that reference the specified principal.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-verifiedpermissions/src/main/java/com/amazonaws/services/verifiedpermissions/model/PolicyFilter.java