@staticmethod
def drop_cols_with_NaNs(df, threshold=0.1):
    """Remove columns with missing values

        Parameters
        ----------
        df : pandas.core.frame.DataFrame
            Two-dimensional size-mutable,
            potentially heterogeneous tabular data
        threshold : float, optional
            Only drop columns in which more than x% of the
            values are missing.

        Returns
        -------
        `pandas.core.frame.DataFrame`
            DataFrame without NaN's
        """
    return df.dropna(thresh=len(df) * threshold, axis='columns')
