Summary
    Gets a flag indicating whether the specified key has
    any entries in the property set.
    
		- Namespace
 - TCLite
.Interfaces  - Containing Type
 - IPropertyBag
 
Syntax
bool ContainsKey(string key)
	Parameters
| Name | Type | Description | 
|---|---|---|
| key | string | The key to be checked | 
Return Value
| Type | Description | 
|---|---|
| bool | True if their are values present, otherwise false | 
