public CallAS7 param(String key, String val) {
        this.parameters.put(key, val);
        return this;
    }
public CallAS7 param(String key, String val) {
        this.parameters.put(key, val);
        return this;
    }
public CallAS7 param ( String key , String val ) { this . parameters . put ( key , val ) ; return this ; }
adds a key/value parameter pair to the call

@param key
@param val
@return this
adds a key / value parameter pair to the call