Add missing function

lib/ios/Param.h

@@ -2,6 +2,8 @@
 
 @interface Param : NSObject
 
++ (instancetype)withValue:(id)value;
+
 - (instancetype)initWithValue:(id)value;
 
 - (id)get;

lib/ios/Param.m

@@ -9,6 +9,10 @@
 
 @implementation Param
 
++ (instancetype)withValue:(id)value {
+    return [[self.class alloc] initWithValue:value];
+}
+
 - (instancetype)initWithValue:(id)value {
 	self = [super init];
 	self.value = value;