[USER (data scientist)]: Nice! Now, let's find out how many matches each player won. Please generate and display a Series showing the number of matches won on grass surfaces by each of the top 10 ranked players in the ATP tennis dataset.
My template of code snippet is:

---BEGIN CODE TEMPLATE---

import pandas as pd
import numpy as np
import pickle
from decision_company import read_csv_file,

# please import the necessary private functions from decision_company first

atp_tennis = read_csv_file('atp_tennis.csv')

# YOUR SOLUTION BEGIN:
<code1>
[COMPLETE YOUR CODE] 
</code1>
# YOUR SOLUTION END

print(matches_won)

# save data
pickle.dump(matches_won,open("./pred_result/matches_won.pkl","wb"))

---END CODE TEMPLATE---

[YOU (AI assistant)]: You got it! We can count the occurrences of each player in the 'Winner' column like this:
'''
import pandas as pd
import numpy as np
import pickle
from decision_company import read_csv_file,

# please import the necessary private functions from decision_company first

atp_tennis = read_csv_file('atp_tennis.csv')

# YOUR SOLUTION BEGIN:
