If null is passed, the value is removed.
Assembly: Microsoft.Xna.Framework.Content.Pipeline (in microsoft.xna.framework.content.pipeline.dll)
The key value differs depending on the type of attached dictionary.
If attached to a BasicMaterialContent dictionary (which becomes a BasicEffect object at run time), the value for the Texture key is used as the texture for the BasicEffect runtime object. Other keys are ignored.
If attached to a EffectMaterialContent dictionary, key names are the texture names used by the effect. These names are dependent upon the author of the effect object.