Mapping IDictionary<Entity, Component> with MappingByCode - nhibernate-mapping

Question

How can I map IDictionary<Entity, Component>? I've done this way:
Map<GeneralResourceType, Quantity>(x => x.BookedResources,
c =>
{
c.Key(ck => ck.Column("ProposedAction"));
c.Table("BookedResources");
},
k => k.ManyToMany(key => key.Column("ResourceTypeId")),
r => r.Component(qc => QuantityMapping.Mapping()));
(where GeneralResourceType is a mapped Entity and Quantity is a ValueObject). But during the call of BuildSession() exception is thrown:
NHibernate.MappingException : An association from the table BookedResources refers to an unmapped class: {MyNamespace}.Quantity.
Seams like it tries to find ClassMapping for Quantity, while value part mapped as Component.

Answer 1

First variant:
Map component in separate class inherited from ComponentMapping generic class.
Map dictionary property as follows:
Map(x => x.BookedResources, c =>
{
//any options access, cascade etc
});
Second variant (inline):
Map(x => x.BookedResources, x =>
{
//any options access, cascade etc
},
x => x.Element(),
x => x.Component(c =>
{
c.Class<Quantity>();
c.Property(p => p.Amount);
c.Property(p => p.Unit);
// any other properties
}
));