code: public static ClearableReference<Skill> createSkillMapping(Agent agent, Class<? extends Capacity> capacity, Skill skill) {
  		return agent.$mapCapacityGetNew(capacity, skill);
  	}
docs: Create the mapping between the capacity and the skill.
  
  <p>This function does not call {@link Skill#install()}.
  
  @param agent the agent.
  @param capacity the capacity to map.
  @param skill the skill to map.
  @return the created mapping, never {@code null}.
  @since 0.6
  @see #createSkillMappingGetOld(Agent, Class, Skill)