DataFrame students
+-------------+--------+
| Column Name | Type   |
+-------------+--------+
| student_id  | int    |
| name        | object |
| age         | int    |
| grade       | float  |
+-------------+--------+

Write a solution to correct the errors:

The grade column is stored as floats, convert it to integers.

The result format is in the following example.

Example 1:
Input:
DataFrame students:
+------------+------+-----+-------+
| student_id | name | age | grade |
+------------+------+-----+-------+
| 1          | Ava  | 6   | 73.0  |
| 2          | Kate | 15  | 87.0  |
+------------+------+-----+-------+
Output:
+------------+------+-----+-------+
| student_id | name | age | grade |
+------------+------+-----+-------+
| 1          | Ava  | 6   | 73    |
| 2          | Kate | 15  | 87    |
+------------+------+-----+-------+
Explanation: 
The data types of the column grade is converted to int.