public ModifyVpcEndpointRequest withAddSubnetIds(String... addSubnetIds) {
        if (this.addSubnetIds == null) {
            setAddSubnetIds(new com.amazonaws.internal.SdkInternalList<String>(addSubnetIds.length));
        }
        for (String ele : addSubnetIds) {
            this.addSubnetIds.add(ele);
        }
        return this;
    }
<p>
(Interface and Gateway Load Balancer endpoints) The IDs of the subnets in which to serve the endpoint. For a
Gateway Load Balancer endpoint, you can specify only one subnet.
</p>
<p>
<b>NOTE:</b> This method appends the values to the existing list (if any). Use
{@link #setAddSubnetIds(java.util.Collection)} or {@link #withAddSubnetIds(java.util.Collection)} if you want to
override the existing values.
</p>

@param addSubnetIds
       (Interface and Gateway Load Balancer endpoints) The IDs of the subnets in which to serve the endpoint. For
       a Gateway Load Balancer endpoint, you can specify only one subnet.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-ec2/src/main/java/com/amazonaws/services/ec2/model/ModifyVpcEndpointRequest.java