<s>[INST] import logging

class SinglyLinkedList:
    def __init__(self):
        self.head = None

    def insert(self, data):
        if not self.head:
            self.head = Node(data)
        else:
            current = self.head
            while current.next:
                current = current.next
            current.next = Node(data)

    def delete(self, data):
        if self.head is None:
            return

        # If the node to be deleted is head node
        if self.head.data == data:
            self.head = self.head.next
            return

        current = self.head
        while current.next:
            if current.next.data == data:
                break
            current = current.next

        if current.next:
            current.next = current.next.next

    def display(self):
        elements = []
        current_node = self.head
        while current_node:
            elements.append(current_node.data)
            current_node = current_node.next
        logging.info(elements)
        print(elements)

    def search(self, data):
        current = self.head
        while current:
            if current.data == data:
                return True
            current = current.next
        return False

    def delete_list(self):
        self.head = None

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

# Test the code
singly_linked_list = SinglyLinkedList()
singly_linked_list.insert('A')
singly_linked_list.insert('B')
singly_linked_list.insert('C')
singly_linked_list.insert('D')
singly_linked_list.insert('E')
singly_linked_list.display()  # Output: ['A', 'B', 'C', 'D', 'E']
singly_linked_list.delete('C')
singly_linked_list.display()  # Output: ['A', 'B', 'D', 'E']
singly_linked_list.search('B')  # Output: True
singly_linked_list.search('F')  # Output: False
singly_linked_list.delete_list()
singly_linked_list.display()  # Output: [] 
```

I'd like to add a new method that finds the index of the first occurrence of a given data in the linked list. What changes would you suggest to incorporate this feature?[/INST]