jadler-core/src/main/java/net/jadler/KeyValues.java
public String getValue(final String key) {
        Validate.notEmpty(key, "key cannot be empty");
        
        final List<String> allValues = this.getValues(key);
        return allValues != null ? allValues.get(0) : null;
    }
public String getValue(final String key) {
        Validate.notEmpty(key, "key cannot be empty");
        
        final List<String> allValues = this.getValues(key);
        return allValues != null ? allValues.get(0) : null;
    }
Returns the first value for the given key
@param key key (case insensitive)
@return single (first) value for the given key or {@code null}, if there is no such a key in this instance