allow direct modification of the access token

Author: adamint

src/commonMain/kotlin/com.adamratzman.spotify/SpotifyApi.kt

@@ -126,6 +126,22 @@ sealed class SpotifyApi<T : SpotifyApi<T, B>, B : ISpotifyApiBuilder<T, B>>(
         suspendRefreshToken()
     }
 
+    /**
+     * Change the current [Token]'s access token
+     */
+    fun updateTokenWith(tokenString: String) {
+        updateToken {
+            accessToken = tokenString
+        }
+    }
+
+    /**
+     * Modify the current [Token] via DSL
+     */
+    fun updateToken(modifier: Token.() -> Unit) {
+        modifier(token)
+    }
+
     /**
      * A list of all endpoints included in this api type
      */

src/commonMain/kotlin/com.adamratzman.spotify/models/Authentication.kt

@@ -23,14 +23,14 @@ import kotlinx.serialization.Transient
  */
 @Serializable
 data class Token(
-    @SerialName("access_token") val accessToken: String,
+    @SerialName("access_token") var accessToken: String,
     @SerialName("token_type") val tokenType: String,
-    @SerialName("expires_in") val expiresIn: Int,
-    @SerialName("refresh_token") val refreshToken: String? = null,
-    @SerialName("scope") private val scopeString: String? = null
+    @SerialName("expires_in") var expiresIn: Int,
+    @SerialName("refresh_token") var refreshToken: String? = null,
+    @SerialName("scope") private var scopeString: String? = null
 ) {
     @Transient
-    val expiresAt: Long = getCurrentTimeMs() + expiresIn * 1000
+    var expiresAt: Long = getCurrentTimeMs() + expiresIn * 1000
     @Transient
     var scopes: List<SpotifyScope> = scopeString?.let { str ->
         str.split(" ").mapNotNull { scope -> SpotifyScope.values().find { it.uri.equals(scope, true) } }