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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def alter_add_column(self, table, column_name, field, **kwargs):
 """Fix fieldname for ForeignKeys."""

        name = field.name
        op = super(SchemaMigrator, self).alter_add_column(table, column_name, field, **kwargs)
        if isinstance(field, pw.ForeignKeyField):
            field.name = name
        return op