void parameter(String name, Object value) {
        Preconditions.checkNotNull(name, "parameter name cannot be null");
        if (value instanceof Observable)
            throw new IllegalArgumentException(
                    "use parameters() method not the parameter() method for an Observable");
        this.parameters = parameters.concatWith(Observable.just(new Parameter(name, value)));
    }
void parameter ( String name , Object value ) { Preconditions . checkNotNull ( name , "parameter name cannot be null" ) ; if ( value instanceof Observable ) throw new IllegalArgumentException ( "use parameters() method not the parameter() method for an Observable" ) ; this . parameters = parameters . concatWith ( Observable . just ( new Parameter ( name , value ) ) ) ; }
Sets a named parameter. If name is null throws a
{@link NullPointerException}. If value is instance of Observable then
throws an {@link IllegalArgumentException}.

@param name
the parameter name. Cannot be null.
@param value
the parameter value