def does_mr_exists(project, source_branch):
    """Checks if an MR for the source branch (i.e. feature/abc) already exists.

    Args:
        project (gitlab.v4.objects.Project): The json response from API checking which MRs are currently open.
        source_branch (str): The source branch to merge into (i.e. feature/#67).

    Returns
        bool: True if the MR already exists, else returns False.

    """
    mrs = project.mergerequests.list(state="opened")
    exists = False
    source_branch_mr = [mr for mr in mrs if mr.source_branch == source_branch]
    if source_branch_mr:
        exists = True
    return exists