putInteger method
Add an integer attribute for the given key.
The attribute key should be a string composed of letters, numbers or underscores ([a-z0-9_]) and can't be longer than 30 characters.
Implementation
BatchEventAttributes putInteger(String key, int value) {
_attributes[key.toLowerCase()] = TypedAttribute(type: TypedAttributeType.integer, value: value);
return this;
}