code: public CreateDirectConnectGatewayAssociationProposalRequest withAddAllowedPrefixesToDirectConnectGateway(
              RouteFilterPrefix... addAllowedPrefixesToDirectConnectGateway) {
          if (this.addAllowedPrefixesToDirectConnectGateway == null) {
              setAddAllowedPrefixesToDirectConnectGateway(new com.amazonaws.internal.SdkInternalList<RouteFilterPrefix>(
                      addAllowedPrefixesToDirectConnectGateway.length));
          }
          for (RouteFilterPrefix ele : addAllowedPrefixesToDirectConnectGateway) {
              this.addAllowedPrefixesToDirectConnectGateway.add(ele);
          }
          return this;
      }
docs: <p>
  The Amazon VPC prefixes to advertise to the Direct Connect gateway.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setAddAllowedPrefixesToDirectConnectGateway(java.util.Collection)} or
  {@link #withAddAllowedPrefixesToDirectConnectGateway(java.util.Collection)} if you want to override the existing
  values.
  </p>
  
  @param addAllowedPrefixesToDirectConnectGateway
  The Amazon VPC prefixes to advertise to the Direct Connect gateway.
  @return Returns a reference to this object so that method calls can be chained together.