code: func (c *Connection) Eager(fields ...string) *Connection {
  	con := c.copy()
  	con.eager = true
  	con.eagerFields = append(c.eagerFields, fields...)
  	return con
  }
docs: // Eager will enable associations loading of the model.
  // by defaults loads all the associations on the model,
  // but can take a variadic list of associations to load.
  //
  // 	c.Eager().Find(model, 1) // will load all associations for model.
  // 	c.Eager("Books").Find(model, 1) // will load only Book association for model.
  //
  // Eager also enable nested models creation:
  //
  //	model := Parent{Child: Child{}, Parent: &Parent{}}
  //	c.Eager().Create(&model) // will create all associations for model.
  //	c.Eager("Child").Create(&model) // will only create the Child association for model.