"""Computes the Coulomb integrals J_{p,q} = (pp|qq) in chemist notation from two-electron integrals.

Args:
    two_body_integrals (numpy.ndarray): A 4-dimensional numpy array of two-electron integrals 
        with OpenFermion ordering.

Returns:
    numpy.ndarray: A 2-dimensional numpy array representing the Coulomb integrals J_{p,q} = (pp|qq) 
        in chemist notation.
"""
You should write code starting with:
import numpy as np

def j_mat(two_body_integrals: np.ndarray) -> np.ndarray:
    # TODO: Implement this function
    pass

