* License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 

 * under the License.
 */
package org.apache.maven.api;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Immutable;

/**
 * A {@link Dependency} that has been resolved, i.e. downloaded to the local repository.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable

package once

// Singleton contains a pointer to T that must be set once.
// Until the value is set all Get() calls will block.
type Singleton[T any] struct {
	v   *T
	set chan struct{}
}

// NewSingleton creates a new unset singleton.
func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

// Run a function containing a MatMul op and check its output.
// If heavy_load_on_streaming_rpc is true, send some rpc requests before the one
// which creates a remote input, to simulate a scenario that the remote input
// is not ready when we start running an op or a function.
void TestRemoteExecuteSilentCopies(bool async, bool remote, bool func,
                                   bool heavy_load_on_streaming_rpc,

    assertThrows(
        IllegalArgumentException.class,
        () -> Traverser.forGraph(createDirectedGraph()).breadthFirst('a'));
  }

  /**
   * Checks that the elements of the iterable are calculated on the fly. Concretely, that means that
   * {@link SuccessorsFunction#successors(Object)} can only be called for a subset of all nodes.
   */
  @Test
  public void forGraph_breadthFirstIterable_emptyGraph() {

    assertThrows(
        IllegalArgumentException.class,
        () -> Traverser.forGraph(createDirectedGraph()).breadthFirst('a'));
  }

  /**
   * Checks that the elements of the iterable are calculated on the fly. Concretely, that means that
   * {@link SuccessorsFunction#successors(Object)} can only be called for a subset of all nodes.
   */
  @Test
  public void forGraph_breadthFirstIterable_emptyGraph() {

}

// getImmediate checks that addr represents an immediate constant and returns its value.
func (p *Parser) getImmediate(prog *obj.Prog, op obj.As, addr *obj.Addr) int64 {
	if addr.Type != obj.TYPE_CONST || addr.Name != 0 || addr.Reg != 0 || addr.Index != 0 {
		p.errorf("%s: expected immediate constant; found %s", op, obj.Dconv(prog, addr))
	}
	return addr.Offset
}

//
//	// update all users's name to `hello`
//	db.Model(&User{}).Update("name", "hello")
//	// if user's primary key is non-blank, will use it as condition, then will only update that user's name to `hello`
//	db.Model(&user).Update("name", "hello")
func (db *DB) Model(value interface{}) (tx *DB) {
	tx = db.getInstance()
	tx.Statement.Model = value
	return
}

// Clauses Add clauses
//

need it so that empty directory does not get deleted...