def add_state_names_column(my_df):
    """
    Add a column of correspondingstate names to a dataframe.

    Params (my_df) a DataFrame with a column called "abbrev" that has abbreviations

    Return a copy of original dataframe, with an extra column.
    """
    new_df = my_df.copy()

    names_map = {"CA": "Cali", "CO": "Colo", "CT": "Conn"}

    new_df["name"] = new_df["abbrev"].map(names_map)

    #new_new_df

    return new_df