src/main/java/org/imsglobal/lti/BasicLTIUtil.java
public static void setProperty(final Map<String, String> map,
            final String key, final String value) {
        if (value != null && !"".equals(value)) {
            map.put(key, value);
        }
    }
public static void setProperty(final Map<String, String> map,
            final String key, final String value) {
        if (value != null && !"".equals(value)) {
            map.put(key, value);
        }
    }
Mutates the passed {@code Map<String, String> map} variable. Puts the key,value
into the Map if the value is not null and is not empty.

@param map Variable is mutated by this method.
@param key
@param value