rest-assured/src/main/java/io/restassured/builder/RequestSpecBuilder.java
public RequestSpecBuilder addFormParam(String parameterName, Object... parameterValues) {
        spec.formParam(parameterName, parameterValues);
        return this;
    }
public RequestSpecBuilder addFormParam(String parameterName, Object... parameterValues) {
        spec.formParam(parameterName, parameterValues);
        return this;
    }
Add a form parameter to be sent with the request. This method is the same as {@link #addParam(String, Object...)} )}
for all HTTP methods except PUT where this method can be used to differentiate between form and query params.

@param parameterName   The parameter key
@param parameterValues Zero to many parameter values for this parameter name.
@return The request specification builder
@see #addFormParam(String, Object...)