rest-assured/src/main/java/io/restassured/builder/RequestSpecBuilder.java
public RequestSpecBuilder addParam(String parameterName, Collection<?> parameterValues) {
        spec.param(parameterName, parameterValues);
        return this;
    }
public RequestSpecBuilder addParam(String parameterName, Collection<?> parameterValues) {
        spec.param(parameterName, parameterValues);
        return this;
    }
Add a multi-value parameter to be sent with the request.

@param parameterName   The parameter key
@param parameterValues The parameter values
@return The request specification builder