func (c Collection) Where(key string, values ...interface{}) Collection {
	var d = make([]map[string]interface{}, 0)
	if len(values) < 1 {
		for _, value := range c {
			if isTrue(value[key]) {
				d = append(d, value)
			}
		}
	} else if len(values) < 2 {
		for _, value := range c {
			if value[key] == values[0] {
				d = append(d, value)
			}
		}
	} else if values[0].(string) == "=" {
		for _, value := range c {
			if value[key] == values[1] {
				d = append(d, value)
			}
		}
	}
	return d
}
Where filters the collection by a given key / value pair.
package collection
type Collection []map[string]interface{}