Write a function to find the occurence of characters 'std' in the given string 1. list item 1. list item 1. list item 2. list item 2. list item 2. list item
def count_occurance(s):
  count=0
  for i in range(len(s)):
    if (s[i]== 's' and s[i+1]=='t' and s[i+2]== 'd'):
      count = count + 1
  return count
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to find the occurence of characters 'std' in the given string 1. list item 1. list item 1. list item 2. list item 2. list item 2. list item
def count_occurance(s):
  count=0
  for i in range(len(s)):
    if (s[i]== 's' and s[i+1]=='t' and s[i+2]== 'd'):
      count = count + 1
  return count[/INST]assert count_occurance("letstdlenstdporstd") == 3
assert count_occurance("truststdsolensporsd") == 1
assert count_occurance("makestdsostdworthit") == 2</s>