Remove duplicates from unsorted linked list in ruby

Ruby program for Remove duplicates from unsorted linked list. Here problem description and explanation.

#  Ruby Program to 
#  Delete duplicate nodes in unsorted linked list
class LinkNode 
	# Define the accessor and reader of class LinkNode
	attr_reader :data, :next
	attr_accessor :data, :next
	def initialize(data) 
		self.data = data
		self.next = nil
	end

end

class LinkedList 
	# Define the accessor and reader of class LinkedList
	attr_reader :head, :tail
	attr_accessor :head, :tail
	#  Class constructors
	def initialize() 
		self.head = nil
		self.tail = nil
	end

	#  Insert new element at end position
	def insert(value) 
		#  Create new node
		node = LinkNode.new(value)
		if (self.head == nil) 
			#  Add first node
			self.head = node
		else
			#  Add new node at the last position
			self.tail.next = node
		end

		#  Make new tail 
		self.tail = node
	end

	#  Display all node value
	def display() 
		if (self.head != nil) 
			print("Linked List Element :")
			temp = self.head
			while (temp != nil) 
				#  Display node value
				print("  ", temp.data)
				#  Visit to next node
				temp = temp.next
			end
		else
			print("Empty Linked list\n")
		end

	end

	def removeNode() 
		if (self.head == nil) 
			#  When linked list empty
			print("Empty Linked list")
		else
 
			#  Auxiliary variable
			temp = self.head
			hold = nil
			initial = nil
			current = nil
			#  Outer loop
			while (temp != nil) 
				#  New last node
				self.tail = temp
				current = temp
				initial = current.next
				#  Inner loop
				#  Remove all node which value is similar to temp node
				while (initial != nil) 
					if (temp.data == initial.data) 
						#  Get remove node
						hold = initial
					else
						current = initial
					end

					#  Visit to next node
					initial = initial.next
					if (hold != nil) 
						current.next = initial
						#  remove node
						hold = nil
					end
				end
				#  Visit to next node
				temp = temp.next
			end

		end

	end

end

def main() 
	#  new linked list
	task = LinkedList.new()
	#  Add tested element
	task.insert(1)
	task.insert(2)
	task.insert(9)
	task.insert(4)
	task.insert(9)
	task.insert(3)
	task.insert(1)
	task.insert(7)
	task.insert(2)
	task.insert(1)
	print("\nBefore Delete ", "\n")
	task.display()
	task.removeNode()
	print("\nAfter Delete ", "\n")
	task.display()
end

main()

Output

Before Delete 
Linked List Element :  1  2  9  4  9  3  1  7  2  1
After Delete 
Linked List Element :  1  2  9  4  3  7