static findClassDeclarationNode(name, ast) {
    if (!name) return {classNode: null, exported: null};

    for (const node of ast.program.body) {
      if (node.type === 'ClassDeclaration' && node.id.name === name) return {classNode: node, exported: false};

      if (node.type === 'ExportDefaultDeclaration' || node.type === 'ExportNamedDeclaration') {
        if (node.declaration && node.declaration.type === 'ClassDeclaration' && node.declaration.id && node.declaration.id.name === name) return {classNode: node, exported: true};
      }
    }

    return {classNode: null, exported: null};
  }
find ClassDeclaration node.
@param {string} name - class name.
@param {AST} ast - find in this ast.
@returns {{classNode: ASTNode|null, exported: boolean|null}} found ast node.