human
Solve the following python programming problem given the following code:
def testRegisterNode(self) : 
    class MetadataTestNodeC (Gaffer.Node) : 
        def __init__(self, name = 'MetadataTestNodeC') : 
            Gaffer.Node.__init__ (self, name) 
            self ['a'] = Gaffer.IntPlug () 
            self ['b'] = Gaffer.IntPlug () 
IECore.registerRunTimeTyped (MetadataTestNodeC) 
    Gaffer.Metadata.registerNode (MetadataTestNodeC, 'description', '
\t\t\tI am a multi
\t\t\tline description
\t\t\t', 'nodeGadget:color', IECore.Color3f (1, 0, 0), plugs = { 
        'a' : ['description', 'Another multi
\t\t\t\t\tline description', 'preset:One', 1, 'preset:Two', 2, 'preset:Three', 3], 
        'b' : ('description', '
\t\t\t\t\tI am the first paragraph.

\t\t\t\t\tI am the second paragraph.
\t\t\t\t\t', 'otherValue', 100), 
}) 
    n = MetadataTestNodeC () 
    self.assertEqual (Gaffer.Metadata.nodeValue (n, 'description'), 'I am a multi
line description') 
    self.assertEqual (Gaffer.Metadata.nodeValue (n, 'nodeGadget:color'), IECore.Color3f (1, 0, 0)) 
    self.assertEqual (Gaffer.Metadata.plugValue (n ['a'], 'description'), 'Another multi
line description') 
    self.assertEqual (Gaffer.Metadata.plugValue (n ['a'], 'preset:One'), 1) 
    self.assertEqual (Gaffer.Metadata.plugValue (n ['a'], 'preset:Two'), 2) 
    self.assertEqual (Gaffer.Metadata.plugValue (self ['a'], 'preset:Three'), 3) 
    self.assertEqual (Gaffer.Metadata.registeredPlugValues (n ['a']), ['description', 'preset:One', 'preset:Two', 'preset:Three']) 
    self.assertEqual (Gaffer.Metadata.plugValue (n ['b'], 'description'), 'I am the first paragraph.

I am the second paragraph.') 
    self.assertEqual (Gaffer.Metadata.plugValue (n ['b'], 'otherValue'), 100) 

    
    

    Fix the buggy line: self.assertEqual (Gaffer.Metadata.plugValue (self ['a'], 'preset:Three'), 3)
assistant
#Here is Python program to fix the buggy line: self.

self.assertEqual (Gaffer.Metadata.plugValue (n ['a'], 'preset:Three'), 3)