title: Remove duplicates from Json response flutter
body: <p>i am unable to remove duplicates in Json. In below Json if title field has same values, i need to remove the duplicate node. IN below json title named "car" was repeated 3 times and i need to remove duplicates based on title field. I followed below stackoverflow links but not solved my problem.</p>
  
  <p><a href="https://stackoverflow.com/questions/54087857/remove-duplicate-value-in-dart">Remove duplicate value in dart</a></p>
  
  <p>Actual Json:</p>
  
  <pre><code>{
      "totalSize": 6,
      "done": true,
      "records": [{
              "attributes": {
                  "type": "ContentVersion",
                  "url": "https://sampleUrl"
              },
              "Id": "123456",
              "Title": "car",
              "Team_Category__c": "Vehicle"
          },
          {
              "attributes": {
                  "type": "ContentVersion",
                  "url": "https://sampleUrl"
              },
              "Id": "123456",
              "Title": "car",
              "Team_Category__c": "Vehicle"
          },
  
          {
              "attributes": {
                  "type": "ContentVersion",
                  "url": "https://sampleUrl"
              },
              "Id": "123456",
              "Title": "cycle",
              "Team_Category__c": "Vehicle"
          },
          {
              "attributes": {
                  "type": "ContentVersion",
                  "url": "https://sampleUrl"
              },
              "Id": "123456",
              "Title": "aeroplane",
              "Team_Category__c": "Vehicle"
          },
          {
              "attributes": {
                  "type": "ContentVersion",
                  "url": "https://sampleUrl"
              },
              "Id": "123456",
              "Title": "car",
              "Team_Category__c": "Vehicle"
          }
      ]
  }
  </code></pre>