docs: function getFunctionBody(methodName, block, argT) {
              var blockCall = types.CallExpression(block, [argT]);
  
              if (methodName === 'let') {
                return [types.ReturnStatement(blockCall)]; // return block(argT)
              }
  
              if (['takeIf', 'takeUnless'].includes(methodName)) {
                var isTakeIf = methodName === 'takeIf';
                return [types.ReturnStatement(types.ConditionalExpression(isTakeIf ? blockCall : types.UnaryExpression('!', blockCall), // condition
                argT, types.NullLiteral()))];
              }
  
              return [// ...
              types.ExpressionStatement(blockCall), // block(argT)
              types.ReturnStatement(argT) // return argT
              ];
            }