public static <TExpression> BsonField push(final String fieldName, final TExpression expression) {
        return accumulator("$push", fieldName, expression);
    }
public static <TExpression> BsonField push(final String fieldName, final TExpression expression) {
        return accumulator("$push", fieldName, expression);
    }
public static < TExpression > BsonField push ( final String fieldName , final TExpression expression ) { return accumulator ( "$push" , fieldName , expression ) ; }
Gets a field name for a $group operation representing an array of all values that results from applying an expression to each
document in a group of documents that share the same group by key.

@param fieldName the field name
@param expression the expression
@param <TExpression> the expression type
@return the field
@mongodb.driver.manual reference/operator/aggregation/push/ $push
Gets a field name for a $group operation representing an array of all values that results from applying an expression to each document in a group of documents that share the same group by key .