lib/swig-tags.js
function pluginBlock(indent, parser) {
  var template = this.args[0];
  var output = '';

  // Register that the template is needed, for 1st pass;
  output += `_context._striderRegister.push('${template}');\n`;


  // Generate code to see if pluginTemplates has block
  output += `var _pg = _context._striderBlocks['${template}'];\n`;
  output += 'if (_pg){ ';
  output += '_output += _pg;';
  output += '} else {\n';
  output += parser.compile.call(this, `${indent} `);
  output += '}\n';

  return output;
}
function pluginBlock(indent, parser) {
  var template = this.args[0];
  var output = '';

  // Register that the template is needed, for 1st pass;
  output += `_context._striderRegister.push('${template}');\n`;


  // Generate code to see if pluginTemplates has block
  output += `var _pg = _context._striderBlocks['${template}'];\n`;
  output += 'if (_pg){ ';
  output += '_output += _pg;';
  output += '} else {\n';
  output += parser.compile.call(this, `${indent} `);
  output += '}\n';

  return output;
}
Plugin block is the tag used to specify that the contents can be overridden by extensions.