to process.

    Returns:
    DataFrame: A DataFrame with synchronized columns.
    &#34;&#34;&#34;
    df=df_.copy()
    if self.target_label:
        df1 = df[df[self.target_label] ==  str(self.target_label_positive)]
        df0 = df[df[self.target_label] ==  str(self.target_label_negative)]
        col1 = df1.replace(&#39;&#39;, pd.NA).dropna(axis=1, how=&#39;all&#39;).columns
        col0 = df0.replace(&#39;&#39;, pd.NA).dropna(axis=1, how=&#39;all&#39;).columns
        col = [x for x in col0 if x in c