'Return corresponding_column for the given column, or if None
search for a match in the given dictionary.'

def correspond_on_equivalents(self, column, equivalents):

    col = self.corresponding_column(column, require_embedded=True)
    if ((col is None) and (col in equivalents)):
        for equiv in equivalents[col]:
            nc = self.corresponding_column(equiv, require_embedded=True)
            if nc:
                return nc
    return col
