'''
Implement a function that multiplies two matrices. The function should handle 
matrices of different sizes and return the resulting matrix.

Ensure the matrices can be multiplied (i.e., the number of columns in the first 
matrix must equal the number of rows in the second matrix).

Raise an error if the multiplication cannot be performed.

Note: functions for this already exist in NumPy, but try to come up with your 
own.
'''

# Your code here