code: public ModifyVpcEndpointServicePermissionsRequest withAddAllowedPrincipals(String... addAllowedPrincipals) {
          if (this.addAllowedPrincipals == null) {
              setAddAllowedPrincipals(new com.amazonaws.internal.SdkInternalList<String>(addAllowedPrincipals.length));
          }
          for (String ele : addAllowedPrincipals) {
              this.addAllowedPrincipals.add(ele);
          }
          return this;
      }
docs: <p>
  The Amazon Resource Names (ARN) of one or more principals. Permissions are granted to the principals in this
  list. To grant permissions to all principals, specify an asterisk (*).
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setAddAllowedPrincipals(java.util.Collection)} or {@link #withAddAllowedPrincipals(java.util.Collection)}
  if you want to override the existing values.
  </p>
  
  @param addAllowedPrincipals
  The Amazon Resource Names (ARN) of one or more principals. Permissions are granted to the principals in
  this list. To grant permissions to all principals, specify an asterisk (*).
  @return Returns a reference to this object so that method calls can be chained together.