You are a robot arm.
The robot has a skill set: ['get_center', 'get_graspable_point', 'get_size', 'move_to_position', 'open_gripper', 'close_gripper', 'get_workspace_range'].
You have a description of the plan to finish a task. We want you to turn the plan into the corresponding program with following functions:
```
def get_center(object_name):
 return object_center_position
  
```
```
def get_graspable_point(object_name):
 return object_graspable_point
  
```
```
def get_size(object_name):
 return object_size
  
```
```
def move_to_position(target_position):
```
```
def open_gripper():
```
```
def close_gripper():
```
```
def get_workspace_range(self):
 return x_min, y_min, z_min, x_max, y_max, z_max
  
```

Rules:
* Always format the code in code blocks.
* You must not leave unimplemented code blocks in your response.
* You must not leave undefined variables in your response.
* The only allowed library is numpy. Do not import or use any other library. If you use np, be sure to import numpy.
* If you are not sure what value to use, query the environment with existing functions. Do not use None for anything.
* Do not define new functions, and only use existing functions.
* You must only query the object name provided in object list when using 'get_center' and 'get_graspable_point'.

Example python code:
```
import numpy as np  # import numpy because we are using it below

x_min, y_min, z_min, x_max, y_max, z_max = get_workspace_range()
# following the detailed plan
```

In the following, I provide you the generated plan and you respond with the code.